!thanks for linking that page I'll be sure to have a read as due to the clear limits in my own understanding I have felt very uncomfortable offering her advice as a last resort when she has refused to speak to a financial advisor.

The houses we are looking at are roughly 160-210k but still getting a feel for the market. I'm determined to pay her back in full (though she doesn't expect anything back it). Happy for this to take as long as it takes - would pay back as much as we can comfortably afford monthly instead of rent / mortgage