Caroline:
I can't recommend the
FastPass+ system more highly, even during times of the year that you'd typically think bring low crowds. You didn't mention when in February you are going, but any time after President's Day sees an uptick in guest attendance.
The benefit of FP+ is not only avoiding standby lines for attractions but now they have added the ability to get one for Princess Meet-and-Greets, Character Meet-and-Greets, VIP Parade viewing, even the popular Be Our Guest restaurant. All of these experiences eat up a lot of time from your day, even with low crowds as they are the most popular "must sees" for younger children who are more likely to go during Value Season when older children are in school.
Definitely go to the My Disney Experience link at www.disneyworld.com before your 60-day-out arrival date to link your tickets, so you can begin selecting your FP+ experiences when your window opens up. Keep in mind that not all FP+ options open up 60 days out, so keep checking if there is something you'd really like to include in your day. And if you have any more questions while planning this first trip, please feel free to come back and ask us.
Wishing y'all a magical vacation!
Whitney