Hi Maki, I'd agree there's a suggestion there, especially compared to 'on the weekend', 'on weekends' or 'at the weekend' which are assumed to be Saturday Sunday. I feel like it's not saying definitely her weekend is not the typical. Another suggestion/possibility I get from it is an emphasis that the time is totally hers to use - her weekend. Another consideration might be 'she likes to spend her weekends cooking', which has (in my opinion) basically no suggestion that it's not a typical Saturday Sunday. Hope that helps, just my thoughts.. Danny

'On her weekends' has no such suggestion to me. If I heard that sentence, I'd still assume the days were Saturday and Sunday.

It may sound weird but I think there is something wrong.