Hiya Sierra!
Thanks for stopping by planDisney! I'm excited to hEAR about your upcoming family trip to the Walt Disney World Resort! Spending time with your sister at the
Most Magical Place on Earth sounds like it will be a blast! And there is no way your Mom is missing out on this fun in February!
When adding a Guest to an existing reservation, it will depend if your tickets and resort reservation are tied together into a vacation package. If so, any Guests added will need to have the same ticket package that the rest of your party has. If added to the reservation, she would be required to also purchase the park tickets.
If you purchased your park tickets separately, then you'll just need to call the
Disney Resort Hotel Reservation line to add her to your reservation. A Cast Member will be happy to assist you in modifying your reservation. Since each room is based on an occupancy of two, there may be a small fee to add her to your resort room.
Another option is to possibly cancel your existing vacation package and re-book a
resort-only stay with your mother included. You can then purchase your park tickets separately for just you and your sister. The only downside to doing this is your tickets must be paid for in full at the time of purchase and they will be non-refundable. This will ensure that your mom can stay with you in your room and not have to purchase tickets if she does not plan to visit the parks.
Sierra, Disney's Pop Century Resort is one of my favorite places to stay! With the addition of the Disney Skyliner, transportation has become much easier to get to the parks. There are also fantastic table service dining options only a short Skyliner ride away at neighboring resorts.
Sebastian's Bistro at Disney's Caribbean Beach Resort is a must-try and absolutely delicious.
Happy planning!
Greg