Party wall act

Other

Hi I have a property that does not have a firebreak wall in the loft, another landlord has bought the delapidated property next door very cheaply and has built a firewall with her other neighbour at her own expense. She has now served a partywall act notice on me stating that she wishes to build a firebreak wall between my property and hers and said I should contribute or we will be in dispute and "she will appoint a surveyor which will mean more expense" if we are in dispute. I replied that I was happy not to have the wall but she had my permision to build it at her expense if she so wished subject to liasing with my tenants due to them working shifts. She has now sent a letter saying that as I will benefit by extra safety and security I should pay as the act says she can ask for a contibution if the adjoining owner benefits, I had interpeted the benefit as a benefit if I actually use the wall to build off or start using the loft as an extra room. It appears that she now wants me to help fund her renovations (poss to comply with lender restrictions) but is treating me in a different manner to the person that is a home owner in the other house with a party wall to her property.
I have had no details of expected costs just that she expects me to pay towards it.
Am I obliged to pay as I have owned the property for several years and had sealed the loft hatch for security reasons when I first bought the property?
She also replaced her guttering and failed to make a water tight connection to mine and said it was up to me to repair it as it was my gutter leaking where she attempted to join to it even though it was fine before her interferance. She has also stated that she repaired a collapsed shared stormwater drain that was discovered when she replaced her down pipes although it has been no trouble as far as I am aware.
Can you please advise
Colin