Chat logging for IMs on phones?

hey guys...well i need your help. my gf has a cell phone its a palm centro...her computer is busted and we're on summer break. her mom doesnt really want her in a relationship and we dont get to see each other outside of school. so basically her mom doesnt want us to really have any kind of contact when we're not in school...so back to the phone. she got a phone recently and it has an Instant Messenger feature on it and we were both wondering if it has chat logging on it. its okay if her mom can find shes been using it and stuff its just if she sees some of the things we were talking about it...it could be bad....so yeah any help would be great. i would just check her phone to see if she has chat logging but i dont get to see her and i cant look myself. any help would be great! thanks