Have you gotten to the root of why she cheated? IMO it is EXTREMELY difficult to trust again once you have been cheated on so it will be a long road ahead. You both need a mutual commitment to work on building trust again. If she isn't pulling her weight in this regard then perhaps you need to see how serious she is about the relationship. I've never cheated and would like to think I won't but if I did and I truly wanted to give it another go with someone I loved I would be pulling out all stops to do it.
Find out why she cheated. Was it because she perceived something wrong with your behaviour in the relationship or was it an opportunistic, drunk off her face type moment? Basically if its the former you need to sort out the underlying reasons and then can move forward together. If she ain't that phased then you deserve better buddy.
Some people are drains and some are radiators... Keep clear of the drains and hug the radiators!