We have the FP rainforest jumperoo. I looked all over the box but it doesn't say anything about an appropriate age for it, it just gives a max weight limit. M is super active--constantly kicking her legs, wanting me to help her "stand," etc. So I think she will love her jumperoo. She's 3 1/2 months. I am thinking we could try it around 4 months. Does that seem too early? When did you put your LO in the jumperoo for the first time?