Sorry to hear your news. To answer your questions we need to know what stage cervical cancer your mum has and what surgery/treatment is proposed.
To fill you in my cancer was very early stage 1a1 so I had 2 minor day case operations and was back to work the next day. However I did appreciate support from my husband at this time. Even if your Mums cancer is early stage like mine then she may like the offer of some emotional support (especially if she is on her own and you are her main support).
It may be that she needs a hysterectomy which can be quite a big operation to recover from so again she may need help especially for a couple of weeks after.
It may be that further / different treatment is required.
If you can find out what stage Cc she has and what her treatment plan is then there will be someone on the forums who can offer more specific advice.
The best thing you can do is listen. I found it difficult to be with people who were visibly and vocally upset about my diagnosis.I wanted to talk about it but I needed to be positive. If you are finding the news hard try and chat to a friend about your upset and concerns and then stay strong for your mum.
It sounds like you are a lovely daughter to be so concerned for your mum's welfare and feelings xxx