They will all have there own requirements, not only the financial aspects (terms and requirements of loans), but also on experience needed and whether yours qualifies.  

She used to live in the house and now lives with us for about 2 years now so the property still qualifies as primary residence.

This way you can weed out the lookie loos and people who aren’t qualified, while also cutting down on the number of times you show the property!

Will having this job qualify me for an FHA loan, even though it’s not related to my degree?

First I would see if they would qualify for a 121 exclusion.

Personally, I would recommend purchasing the primary residence first, mainly because of how the DTI is calculated.Scenario 1: If you were to purchase the STR first, and then the primary residence, you will likely need to qualify with the full payments on both properties depending on your timeline.

Non-occupying co-Borrower: A non-occupying co-Borrower on an existing FHA insured Mortgage may qualify for another FHA-insured Mortgage on a new Property to be their own Principal Residence.

.- lower turnover- easier on the units when they do move- quiet and less disturbance than traditional, younger- for fixed income, consider partnering with the local housing authority for SEct 8 vouchers, then raise rents accordingly - guaranteed money & the Sr. only pays a portion (if they qualify)Traditional renters- Higher turnover- Higher turn costs- More volatile - higher bad debt- More drug related activities- Adding in children that are hard on units- Higher eviction rates and legal costsConsider all angles before making a decision with the changes. 

Yes, we have been doing lease/purchase and lease-options deals for over two decades.The rent+own strategy is particularly relevant when prospective buyers are having a hard time qualifying for a mortgage, either because mortgage rates are high or because prices are rising.Kinda sounds like both are happening right now, doesn't it? 

The property is ~75% occupied, so it wouldn't qualify for agency programs.The seller is extremely motivated and may even consider seller financing her equity.