For example, if you can define the data points that you want to capture (location, age, property type, etc.) and ask BP members to share that then you could aggregate it and create value by offering the aggregate data, via a subscription to other interested parties.

(There is a good chance)   See section 5530 of the PA statute of limitations for mortgage debt.https://www.legis.state.pa.us/WU01/LI/LI/CT/HTM/42/00.055..HTMThe cost of a Quiet Title suit is usually a few thousand -if the other party does not respond. 

@Brenden MitchumI would suggest that you reiterate your conversations with the seller via email, cc’ing the listing agent so everything is known to all parties and in writing.  

Anyway, we decided on a refundable deposit, proof of it being a "service" animal, and an addendum that she sign and return that basically protects both parties.

My mentor highly recommended against a 50/50 split since he has had issues in the past where both parties had opposite opinions which ended in a stalemate and no action being taken. 

I would like it the benefit both parties but most importantly the best way to benefit her. 

California is a lien theory state... so based upon that, a mortgage or deed of trust executed by one joint tenant would not sever the tenancy unless the property was sold at foreclosure prior to the death of the party who incurred the lien.If the other owners executed the HELOC they would be pledging their own interests as collateral... which I doubt is the intention.

Post notice of past due rent to get the eviction party started.  

One party can pay it or it can be split between the buyer and seller-spell it out on the contract and get more info from the closing attorney or title company in your area.

Anyone with advice on a way to structure that makes both parties comfortable?