I think it would give her a great chance to let everyone see what a fun person she is - I definitely hope she goes for it Sock it to them Judy!
It would be a huge risk. On one hand, it could be the opportunity to finally get across to the general public that she does have a job in tennis other than sitting in Andy's box. On the other hand, she'd be getting the gig because she's Andy's mum, not because she's Fed Cup Captain, so it simultaneously undermines that message. If she was confident of staying in a reasonable number of weeks, it's likely to pay off. If she goes out early, it would be another stick to beat her with.
Personally, I think more and more people are getting to know and like Judy for who she is, and what she's achieved other than giving birth, and I think it would be better for her to keep on doing what she's currently doing media-wise for the time being. Perhaps she could do it in another couple of years time when she's built up more of a reputation for her own day job? This all assumes she's got the time.