I want to gps my step mom?

That would be difficult, but it might be possible for your dad to GPS track her with her cell phone, especially if they are on the same cell phone plan. If he talks to the cell provider, he may be able to get them to help him set it up so he could track her from a smartphone or computer. I know Verizon has a service like that. I think it's called Verizon Family Locator. Hopefully you have Verizon. If not, I think there are some online services that he could sign up for and use. They have services like that for parents that want to keep track of their kids. If all else fails, he could try contacting Cheaters at a href="http://www.cheaters.com/" rel="nofollow"http://www.cheaters.com//a and they may be able to track her and see if she's up to no-good. No matter what you do, your dad would most likely have to help you do it. Hope something here helps you. Good luck.