Loft fire wall

Other

Anyone have any ideas on the following:
A terraced house next to one I own was purchased by a lady very cheaply and she is now renovating it in order to let it. She has had the work men in and had the guttering replaced and built a fire break wall between her and the person on the other side of her, she has now come to me and asked if I will build one my side at my expense although she had the one built on the opposite side and asked for no assistance from the other owner. The other thing she mentioned was that she had replaced her guttering and could not match up to mine so in her words "You (meaning me) will have to sort it out" I knew there was no fire break wall and it was not mentioned 5 years ago when I bought the property but it now seems like she has bought a cheap property partly as a result (was on her survey)and wants remedial work done at my expense I am not sure how to play it at this moment in time.
Thanks Colin