she's been looking on my twitter?

[Cheese]

She probably just doing this because shes worried about you ( all mums are ) also maybe you just paranoid. Anyway if you think youve got no privacy and as you say your a nice person tbh, Confront her ask her if shes been reading it or you could say i know youve been reading my tweets ect ect or you could hint that you know shes reading you tweets or even write a tweet about something that could either be like "My mums reading my tweets " make her feel guilty or so she knows you know or you could be like " cant believied what happened today, my mum would kill me if she found out" then she would just have to find out , and you could be like aha i knew you were reading my tweets.