Having trouble with apple ID on ipod and iphone?

So i have an ipod, and my mom has an iphone. The other day i downloaded an update for her on her phone, and it asked for an apple ID, so i just put mine in not thinking anything. But if i ever text anyone off my ipod, she recieves the entire conversation on her iphone. My friend said i have to go to a verizon store and ask them to disconnect her iphone from my ID, but I was wondering if there was an easier way that i could just do it without going to the store? Thanks!!