is it wrong or disrespectful?

I see a lot of people that ask for prayers when they have something going wrong in their life. I personally don't believe, but I do send up a prayer for them. Me and my husband were talking and neither one of us knew if it was the right or wrong thing to do. I mean if I don't believe does it mean that my prayer for that person isn't valid. I just kind of hope that the god they believe in will answer prayers from everyone and help that person out. I don't believe in what they believe, but I will do anything I can for anyone and if that's what they need at the time I'll do it. Is it disrespectful or wrong of me to do this if I don't believe?