Seems like too much work for too little return UNLESS you own the property, or perhaps have an option to purchase the property allowing you to capture any increase in value.   

Who owns the solar panels and what's my liability if I continue with the purchase?

Purchase price: $220,000 Cash invested: $45,000 This is a 2 bedroom, 2.5 bathroom rental that I purchased.

Quote from @Jeffrey Bourque: ARV $350,000 - $400,000 3bd 1 bath 800sqft estimate rehab $70,000 purchase price $200,000What are your thoughts and should I do it? 

It allows you, the wholesaler, to transfer your rights to purchase the property to an investor.

This implies that if I had confidence of better than normal appreciation or ways to add value, I would purchase a negative cash flow property.  

Sadly, I might have to wait until early 2025 for #5, as my funds have dwindled from purchasing 1-4.

Sure, they may be able to grow to a very moderate size,  add a few units, or trade up to a larger investment, but as for real scalability: NO.Why?  

Purchased as an asset sale in October 2019 as a buy/hold investment.

Us: We want to buy the property, fix up the (3) apartments not occupied by her parents to generate rental income.QuestionsMy thoughts are to work out a deal where we purchase the property from her parents without taking a loan from bank.