Joint mortgage owners split

Willy72

Me and my ex girlfriend bought a house in 2007 with 10k from our business on a self cert mortgage, when we bought the house my mum gave as a gift of 30k, 10k back to the company and 20k for refurbishments ( my mum has recently passed away) and we lived happily for 2 years. Unfortunately we split in 2009, various things transpired and my ex never paid the mortgage for 6 months (it was a so called gentleman's agreement until we sorted our business out that she paid the mortgage) and upon not paying the mortgage we ended up in court with repossession hanging over us. In a nut shell I was awarded to live in the property so long as I could pay the mortgage and the arrears, to which I did. Now I have lived and paid the mortgage solely for the last 7 years and all bills and up keep of the property. Now we are in a predicament where we need to sell but obviously we are going to argue over how much each gets. We bought for 100k minus 10k deposit, 55k is left on the mortgage and the new value of the house is 110k. My question is if we sell will I have to give her half of the proceeds or will I get what I solely paid into it plus any profit minus fees. Hope I explained it ok.