Need help from being bitter

So for a long time I have been wanting to decorate a nursery with elephants when ever we have a baby. Not sure why but I want it. Yesterday was shopping with my mom I found this elephant that plays peak a boo and stuff so stinking cute. My mom saw me looking at it and loved it. So she got it for my nephew. I love my nephew so much but god why did it piss me off so much that she got him this elephant.(we have been trying for over a year) Anyone else do this? Ideas how to get over it?