Thanks, Sunnyshores.
She hasn't been employed for decades, but could get a character reference from someone from her old church.
Would you accept me as guarantor? My salary is just under 30 times her maximum budget, and my total income (inc unearned) is over 40 times. I also have a mortgage, which is a bit under half of the maximum that she wants to pay. (So, if I had to pay my mortgage and her rent, my total income would be a squeak over 30 times the total housing cost). (My DH also contributes to our mortgage, but is self-employed, so demonstrating income isn't as trivial as waving a payslip around.)
Will it be an issue that she has already sold her house (she's visiting family abroad at the moment, then will go into holiday let), so she's got no current address?
She's got about ten years of the max monthly rent in the bank, having recently sold her house! So I'm pretty confident I won't have to bail her out. But I appreciate boxes must be ticked.
We did sell-rent-buy a few years ago, and ended up using the same agent when my FIL did the same. The agent remembered us - it would be great if they had something suitable on their books again!
Without wishing to sound too blunt, DM doesn't make a good impression. Social skills are not her forte, she gets very nervous, and she has an interesting take on fashion. With FIL, I did the ringing round - his hearing is poor, so it was just easier. I think it would be best if I did the same again.