MDE, customize magic bands for group question

[HuskerFaninIL]

I have my account linked to two other groups who are traveling with us. It's time to pick our band colors/names and for some reason I see my four bands and my in-laws two bands, but my SIL's family doesn't show up. Their reservation for room does show up on my account though.

I'm not overly concerned about the MB customizing thing, because they could do that, but I'm super concerned that I won't be able to make their FP+ reservations.

Is there something we're missing on the connecting part, and how can I be assured I will have the power to do their FP+ ressies come Dec 7th?

Thanks!