@Christopher Hall, @Seth Williams mentions two things that are worth extra comments.

Not a fun topic to think about, but if you want to keep the property and they want to sell, it's best to know now, before you go into a partnership with them.If you go this alone, be prepared to pay 100% of everything - that way any money your mother gives you is extra, not something you're counting on to pay the bills.It is admirable that you want to help your mother, but make sure you can afford to do so without jeopardizing your own finances.

What I get caught up if you put the minimum down on FHA and have the extra cost of Mortgage Insurance is it worth it?  

Goodbye, mortgage interest deduction, hello extra cashflow.And THAT's when I finally cracked.

The extra two units may make it a steal.

If the roof is really high most will charge extra.

That extra 15K brings a lot of square footage, so I don't worry about it appraising.

LLCs aren't particularly difficult. I

A few extra dollars to a handyman is certainly cheaper than having a tenant not renew because these requests were not given the proper attention.

It comes down to 3 things...Screening, screening and screening I can't stress that enough make sure to ask prospects the right questions and also verify income, job history and rental history.I used to check people's social media for extra due diligence.