Hey There, Hi There, Ho There, Janet!
You are as welcome as can be here at planDisney! How exciting that you have an upcoming visit to Disney just around the riverbend. I always say you are never too old (or too young) for Disney. Whether you are one of the youngest Mouseketeers or a kid at heart, Disney is magical for everyone.
Janet, I double checked with a Cast Member about your question. If you booked a vacation package, essentially the package options apply to everyone on the reservation for the entirety of the vacation. So, whatever is included in your package (i.e. room, theme park tickets,
Memory Maker, etc.) can't be separated out per person or per day. To add your son and his girlfriend to your room, you would have to add them to the package and choose the same options for them. Then you would pay the package price for two additional people.
If you booked a room only at
Disney's Pop Century Resort, and purchased theme park tickets separately, the Cast Member said that once you are at the Resort you can tell the Front Desk team that you will have two extra Guests in the room for one or two nights. There will be an increased cost for those two nights. However, this would give you the flexibility to add them just for the dates they are staying. If you modify your reservation online, it is going to add them to your room for the entirety of your stay, which may impact the cost of every day. This is why the Cast Member recommended doing it once you are at the Resort, as the Front Desk team can wave their magic wands and add them for only the night or two in which they are staying.
One other thing to note is that Disney Resort Hotel rooms can't go over capacity. So, as long as you have a room that can sleep four, it should be okay for them to stay in your room.
I hope this helps you, Janet! If you have any further Disney vacation planning questions, come along and sing a song and join the jamboree here at planDisney. We will be so happy to help you!
See ya real soon!
Keri