Ex-GF's father diagnosed with cancer. Suggestions?

[hamsamich]

This is a bad idea IMO. Since she is preparing to bury her father there really is no up side to this for you at all. You can be her rock through this very difficult time but by the time her father makes his grand exit and she is ready for anything else in her life you will have hung around for several months for.....what?
If you truly liked her old man I would consider making one trip out to see him to pay your respects before he is too ill. This really only applies though if he liked you too.
It just sounds to me like you are getting ready to devote tons of time to this because you want her back and all the while she will get a free ride.....tons of support from someone she knows and trusts but can discard when she's done with the 'well I never said we were getting back together' excuse.