Just buy her the gun that she wants. Take her to the shop and have her hold them all as that makes a big difference. Then, if she wants a p-22 in pink, don't hesitate to get it (preferably as a surprise given after a nice Friday night date).
Frankly, if it's a reasonably reliable gun (and it seems like this is a range gun) don't stand in the way. You can always sell or trade it for something else down the road.
As for the color, it would make no difference to me. We all have our preferences to blue, stainless, parketerized, green, etc. Pink is no different. As far as having a new born, congrats! But, it doesn't make a difference either. He/she needs to be taught what is a real gun vs fake, and that shouldn't be based on color.
So, don't wait - go get it!