Sloping gardens

Veggie, I actually met the vendor when I viewed. She was potting up plants outside while the EA and I wandered round - that's how I knew I was onto a gardening winner! We had a bit of a chat in the kitchen afterwards so I know a bit about the history of the house. I thought I would post her a little card saying thank you very much for accepting my offer and that I'm really excited to be buying a house that's been so well looked after. Firstly, I think it's a nice thing to do and will be reassuring for her that she is leaving her home of the last 64 years in the hands of someone who will care for it. However, from a more hard-headed point of view, I would also like to make it harder for anyone to gazump me or for her to worry that things aren't proceeding quickly enough and put it back on the market (because mortgage offers expire after three months and the sale can't complete until October, I can't make my mortgage application yet, and that also means I can't easily get a survey/searches done as they will be dependent on the lender - I have an agreement in principle, but that's not a sure thing until a mortgage offer is actually made...)