Baby favoring one side?

Had our 2 month check today. Everything is good, but my daughter favors one side over the other. Doc isn’t too concerned but said we have to force her to look the other way so her neck muscles develop more.

Now I feel like I’m failing her because she’s a little behind where she should be and I’m scared she won’t get those muscles developed. She does still look both ways and can slightly hold her head, but is wobbly. Doc says she is “lazy with her neck”

Anybody else in this situation?