Sharla

You are part of a headquarter group that allowed better pricing when you booked.  This shouldn't be confused with a group cruise type affinity group.  It's a sort of group available to an agency based on their affiliation.  It's likely that group filled up so when you parents booked they were booked as a regular FIT conventional booking.  So yeah you can't mix group bookings and FIT bookings. 
You could have a conversation with your TA about it but it's likely just easier to create a Royal login for them and use that to book their stuff.
If they hadn't used the group when you booked you would have likely paid hundreds more so it's a good problem to have. 

On our one and only Star class sailing our cabin host was amazing, really working in tangent with the Genie. Albeit the gratuity for her was "included" with the higher cost of said cabin, we felt she was deserving of an additional monetary gift.  2 nights before debarkation, we saw her in the hallway, "training" another host for our cabin. We actually knew the second young lady from another sailing. We stopped & chatted to find out our host for the week was finished that evening as her contract had ended & she was going to pack the next day get everything in order & leave the day we did. I would have been so upset as she was most gracious. We went right back in the cabin & grabbed the thank you card we had brought on board with us and placed her well-deserved gift within. I then gave it to her in the hallway that very evening with a huge hug, so appreciative that the universe works in mysterious ways. I would have felt ugly if she had left without saying goodbye. 
So, like@WAAAYTOOO stated, especially when we B2B we tip along the way if warranted. We don't do it with future expectations in mind but for amazing service we are receiving there & then. Enjoy your sailings, I love B2B's.

i have a great MEI agent Jacki York  that I work with. thanks

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

They do, unless you're sailing in concierge.

They do, unless you're sailing in concierge.

It sounds like you need one. 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

This happens a lot on folios. I truly do not understand the check out system for towels. No one is stealing those crappy towels!
 

No need for a middle ground.  Current ground has it free for all of the hours it is open.

The survey asking if we will pay money for Sorentos made me think why to stop there. Here some more creative ideas for RCL:
Weight the plates in the WJ and pay by the pound. 
Want Emuster ? Pay extra otherwise you are back to the regular crowded muster.
All cabin doors to be removed , want privacy ? It's extra, diamonds will get free transparent shower  curtains,  D+ will get free transparent door and pineapples will get a real door but without a latch.
Quest challenge lidt can be purchased the day before , same for Love and Marriage. 
Tender boat tickets will cost money,  people will be able to swim to port for free. 
For dinner time you can choose between 5 to 5:15 PM , want another slot ? It's extra.
Extra charge the comedy show if you don't want to be the star of the show.
Jacuzzi will be coin operated,  the good news, you can use your key to charge it to you room.
The flowrider will still be free you just need to pay if you want it filed with water.
At the end of the cruise at the exit you will need to be weight , every extra pound you gain during the cruise will be charged. 
Charge 4500$ for a 7 hour use of the over the water cabanas , oh wait ...
 

Sometimes group space is contracted by large companies such as that. We can even do that sometimes with MEI because we can book into our consortia group space. But it's not on every ship/ sail date and it's generally limited to 2 guests per room.
That being said, Cruises Only probably has contracted space, just check what is included and the terms. I agree with other posters, I don't know what happens if something goes wrong and you're booked with them.

While I'm not actively trying to make this reply a plug for the travel agency that sponsors this forum, I do know what happens if something goes wrong and we're represented by our MEI agent.  The amazing service we received when the covid pandemic shut down happened was incredible.  Despite the fact that our agent was dealing with many, many clients (a lot with more lucrative bookings), we always felt we were her #1 priority.
A quick web search of "Cruises Only" shows me their title of "America's Largest Cruise Agency".  I'm sure that's a good thing, but I'm skeptical of the one on one service we would receive.
My wife and I have made the conscious decision to stay loyal to our agent who stood by us when all cruising came to a complete stop. 
 
 

Nice article, but I much prefer this one.
 
https://www.royalcaribbeanblog.com/2023/07/24/royal-caribbean-building-new-smaller-cruise-ship-deeply-our-consideration

They aren't required but if you have one I recommend bringing it. Because if something happens on the ship better safe than sorry, that's my take.

They aren't required but if you have one I recommend bringing it. Because if something happens on the ship better safe than sorry, that's my take.

Finally getting to ALASKA! Had this trip all planned out and paid for in 2019 for a land and sea cruise in August of 2020. Well, that didn't happen and I'm sure you know why. This past June my wife says let's go to Alaska, this year. Nothing like waiting util the last minute. So, I go online and the same trip we had planned before is  booking 29 August to September 8 at a price I couldn't refuse and an aft cabin to further sweeten the deal. I called Michelle, she still had the trip in her computer and we booked it. Oh. one other thing, Aug 29 is my wife's birthday. Nice. 
Here's my question. After the land portion (Denali) we end up in Seward to Board the Radiance for the south passageway. The Radiance will be coming from Vancouver on the north passageway to Seward for debarkation of those on board. Where do those folks go/do once they are off the ship? Thanks.😎

They aren't required but if you have one I recommend bringing it. Because if something happens on the ship better safe than sorry, that's my take.