But if your sister gets a mortgage through one of them and keeps her credit rating good for a year or two, she should be able to get a better rate, either from the incumbent lender or by re-mortgaging.
Thats correct.... your sister can take out a loan with these lenders...
Provided she keeps her repayments up to date for the next 6 to 12 months (Based on income and employment situation remaining the same) there should be no problem in reducing the rate....
She will be required to keep payments up to date for at least 18 months before being considered by one of the prime lenders...
If she has a judgement against her name she will have to remain with the lenders for 2 years before considering applying for a new rate or switching lenders..
These rates range from approx 4-8% depending on your sisters credit rating