Family with special needs adult looking to buy second home.

[Chris Iley]

My mom is looking to buy a second home for herself, single and she just retired.  Would like to leave my special needs sister at her current home to live with my sister for at least a year while my sister finishes college and figures out her own life.  But we would not want to sell the house at any point, eventually turning it into a rental unit.  I would like to refinance her current home once my mom purchases another home.  She will use the money for home upgrades to both houses.

Her Current house - Value $200k, remaining loan $58k. Total monthly payments (mort, tax,ins, hoa) is $950

She would like to purchase a second home in the 175-200k range.

Between moms pension/retirement and my sister disability, she makes about $5000/mo, she has a pretty sizeable 401k  as well.

We also own another house (myself and mom on title) that I'm getting ready to move out of rent out, its value is about 400k, no mortgage but i do have a 175k HELOC on. It does have an adjustable rate, which I'm concerned about in the current environment, as of last month was still only 2.99%. In this area, I'm confident i can rent the home for $3000ish / month.

I read about something called a Family Opportunity Mortgage, which seems like it could be a great option.  She has been looking for a home for.....years now.....so the lender she was pre-qualified for (before she retired) just told her with her income she can still qualify.  Idk if they do the Opportunity Mortgage however.  

I guess I'm not sure what the best option might be for us.   I have some rental units, so I've already made it clear we are not selling anything ever,  Trying to figure our how we can get the most money out of our current holdings by refinance while buying another property with the least amount of money out of pocket right now.