Baby jumpers?!

I'm going to post this in second time moms since you guys may have better advice than us first timers 😜

I was given a jumper similar to this one and was wondering if it's safe to start using? My daughter will be 15 weeks old tomorrow. I read it's good to strengthen leg muscles, but then I'm also reading to not put your baby in one of these because it's bad for their legs and spine (I swear sometimes Google gives me more questions than answers!) My daughter has great head control, but trying to work on the leg strength. Yay or nay to the jumper?