"Borrowing" Magic Band for FP+?

Our family of 8 is headed to WDW May 27-Jun 3. We will all have 5 day passes but on one of our MK days 3 of us are going to Universal. Can I make FP+ reservations for them and use them even if they aren’t going to the park that day?

I was planning to make 3 reservations with them for my sister and her daughters for Peter Pan and the two princess meet and greets at the castle. Thoughts?

Also, if the kids don’t want to go on a ride, do I need a FP for them to stand in line with the adults?

As long as you have tickets linked you can make and use FPs. Do they have an extra day of tickets they will not use?

The kids would need FPs, but can you use rider swap?

Yes, even though we all have 5 day passes, my husband and sons are only going for 4 days. I thought we could make use of their FP for a few things since we already paid for the tickets. I just wanted to make sure they didn’t have to enter the park for us to use the FP.

We can use rider swap but would prefer to stand in line together.

Rider swap would allow the children to do extra attractions. You could book and adult and the kids to do things like Disney Junior or a show and then up to three can do the swap later.

You do not need to have a magic band scanned to use the fast passes.

If you want kids to wait in line with you they will need a fast pass if you are using the fast pass line even if they are not riding. Due to past abuses of systems everyone entering fp line must have a valid fp to enter. If using rider swap an adult will wait with them outside the ride so no fp needed.

I was thinking about this. Are they too small to ride? I do not know if they will let them in the line with a FP?

No if they are too small to ride they will be refused entry to the line.