If someone can't do her normal job and is now on IB after SSP just ended can she do some PW for another employer?

Can't see that there is any problem with this in the IB rules - contractual issues generally have no bearing here, once SSP has finished. Might be an issue with the first employer though. There may be contractual restrictions on outside employment and even if there aren't, there might be some explaining to do. It may be a good idea to clear it with the first employer, assuming your client wants to retain that employment.

Richard Atkinson