startling??

[Party-of-five]

Ok just to say that startling is one of them words that doenst look right when you write it...Anyways my 3month old DD doesnt spend much time on the floor hardly any really she is either in her swing, on her bouncy or in my arms.
Now when I put her on the floor she holds her breath, goes all red and stiff and then screams!!! really screams!!
This will pass right?? reasure me someone?
its not like she will get used to it because i cant watch her be upset like that so I dont put her down on the floor
The reason she hasnt spent much time on the floor is because her darling big sister see's her as an easy target but she is getting much better now.