Repossession or not?

Paul1706

My girlfriend currently lives with her ex partner who contributes nothing towards the mortgage repayments, or the household bills. He is currently employed and although he doesnt earn a massive salary still has an income. He only lives in the house on a weekend as he works away during the week. The house is on a part buy part rent scheme, where she pays half of the mortgage and rent to the finance company that owns the remaining 50 % share.
She is struggling to make the payments on the rent and also wants to sell the house and start afresh. Her ex partner does not earn enough to be able to take over the repayments and neither does my girlfriend.
There was a recent offer on the house but the problem that she has is the finance company will not let her sell the house at less than the valuation and in the current climate nobody is likely to offer the full asking price. She has discussed the problem with the finance company and has also discussed the possibility of the finance company buying the other 50% share in the house or letting the house get repossessed. The finance company appear to be stalling on making a decision.
What do you think she should do? Will the repossession have any implications on us getting a house together in the future. I have an excellent credit history.