Normally the weight limit is around 25 lbs. My second child didn't outgrow hers till she was around 16 months and she was short . My son outgrew his just before his first birthday. It really depends on how fast the gain weight. Keep in mind if you use FP swings allot the motors tend to go out rather quickly.
We used ours for about 5-6 mos. after that, baby was starting to roll and try to sit up and it made me nervous. We used ours A LOT for those mos and never had motor issues so it really is hit/miss.
Re: outgrow FP swing?
IVF #1 ET 1 d3 embryo 10/30/11 BFP
3 Embryos frozen (1 d5, 2 d6)
DS born 07/29/12
FET #1 ET 1 d5 embryo 02/10/15 BFN
FET #2 1 d6 embryo didn't survive thaw, transferred last d6. CP