put her on a mattres on the floor n surround it with pillows? try not to put in walker for too long, its not good for her hips. And you should let her be on her tummy more to let her practise crawling.
What i did thn was turn on some music, give her some toys and let her roll around the mattress on the floor. Beneath the mattress i covered floor with puzzle mats. Put some toy mirror for them they like it.
I dont reallly fancy playyard cos it blocks their view. I personally believe in lesser restrictions, and confinements. Watever it is, play yard or not, babies must be constantly monitored, at all times.