agreement in principle - but not sold yet?

virgin_moneysaver

My sister's house is up for sale & she's seen the one that she wants to offer on once she's sold (hopefully it'll still be for sale) - we have an appointment with her current motgage lender on Monday & if they have a decent 3yr fixed rate are they likely to agree it & hold to that rate for a period of time whilst she's waiting to sell - also should she go in armed with quotes from the websites of chelsea B/soc, yorkshire B/soc & the like as they seem to advertise good rates?

many thank - she needs a bit of moral support as when she bought the house originally it was with her then fiance & just asked her lender then to give her more so she could buy him out, she's not 'shopped around' before & is a bit nervous