I would consider trying to learn about her situation and her motivation(s) for selling before talking about price. That is, seeing what is important to her and crafting your pitch around that. For example, she may not want to mess with painting and sprucing up the place that might be needed if it were to be listed with a realtor. Or, she may be in a hurry to sell. You mention some of these things so I think you're on track.
In any negotiation, if I don't think I have the upper hand I make an extra effort to sell myself even if I'm the buyer. I try to find something to be complimentary about. For example, "You've done a great job at taking care of the place. It really shows!", or "I think you picked the best condo here. The location is great!". For you this is a business but for her it's probably emotional and if she likes you I feel that she'll be more likely to open up and negotiate.
And lastly, "no" only means "no right now". She might need time to think and verify some of what you're telling her. Give her a few days then call back to check in.
Good luck!