In the US the recommendation is 6mo....some pediatricians still recommend 4mo though that isn't right anymore
What she was probably doing with her tongue is the tongue thrust reflex and one of the signs that they are ready for solids is when that goes away, it's just her body telling you she isn't ready for anything but milk right now. 3-4 mo it is very common for them to start waking again because it's one of the biggest growth spurts they have. I would try upping her milk and just feeding her that on demand and see where she is in a couple of weeks. But here are some good things you can read so you know why the recommendations are what they are...hope it helps
https://www.askdrsears.com/html/3/T032000.asp
https://babyfit.sparkpeople.com/articles.asp?id=712