If you have not done so already, I would speak to your solicitor and find out whether or not the property has planning permission to be split into two flats and also how much it would cost to split the title and create two long leases on the flats within a separate freehold for the house.
Whilst it is potentially possible to find a lender willing to grant a mortgage as the property stands, you will have a lot more choice if you want to mortgage a standard leasehold flat.
Bridging Loan/Short Term Finance
You may find it necessary to obtain some short term bridging finance to enable you to purchase the property and then to remortgage once the title has been sorted out.
Strangely, it would actually be easier to arrange a mortgage if the property was going to let and neither you or your daughter were going to live in it.
I believe we can help you and that you would benefit from speaking to one of our independent mortgage advisers. Please call 0808 271 4723 and one of our consultants will be able to advise you on your situation.