How do you ask your mum to be more involved in helping with the baby without hurting her feelings?

I personally feel that you cannot really 'force' your mum to be more involved if she doesn't like it or want to. There are some grandmas who love taking care of grandkids but there are also grandmas who doesn't want to. I think you should talk to her to find out about how she feels about it and also if you really need help, you can ask her nicely if she is able to help you. If not, then I'm afraid you have to either do it urself (it's your baby after all) or look for someone else (eg. a nanny). No point ruining the relationship between your mum and you because of this.