Unfortunately, she is not liable to pay the mortgage within the finances of the relationship in respect of a house if she is not living in the house. You have the benefit of living in the property and hence you have the burden of paying the mortgage.
If you don’t pay the mortgage however she does remain liable to the lender who will chase you both for repayment on the basis that you are jointly and severally liable for the debt..
You are entitled to have the cost of any improvements or capital repayment on the mortgage which you make after you split up, taken into account if the house is eventually sold.
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