My mam has just been diagnosed with bladder cancer but don't know what stage its at till the biopsy results come bk I'm concerned she has been sleeping a lot and has lower leg pain can you give me any advice please as I am worried

You need to wait for the biopsy and a chat with her own medical practitioner.

I'm scared in case its eating away at her she is also in bad health with c.o.p.d

You need to wait for the biopsy and a chat with her own medical practitioner.is there anything I should watch out for in her she is also in bad health with c.o.p.d

Two suggestions:
Go with her to her doctor visits if she will let you.
Learn all you can about bladder cancer from research online, in addition to what her doctor tells her.
Pain down her leg could be anything - something hitting a nerve possibly, rather than spreading cancer. Or just from sleeping a lot. And COPD can lead to fatigue if she isn't getting enough air in her lungs. And so on. We can't possibly know all that is going on with her and what is being done so far.