Having done all the above ticket linking, and added her to your friends and family list, if you want to you can then go into your fastpasses and use the MODIFY option. Then I think there's an option to change party or add to party, and if there's an available fp you can simply include her. However you may need to try and get overlapping times instead.
Say you have Splash for 11-12, you might not be able to get exactly the same for her but you might get 11:15-12:15. Then you can all ride together for a 45 minute window (slightly more if you include the leeway but I never plan on that).