We would also like some advice on whether the decision of creating an LLC or not would depend on which strategy and niche we chose? 

If she had 3 BR units, she would have to consider a different demographic and could not base her decision on familial status. 

These decisions take time and add a ton of value if done correctly, so if you were doing that, your adding value.

Be an employee of the owner working on a salary with NO bonuses or commissions.You don't mention what this girl's legal setup is, but you don't want to get in bed with someone just because the tenants love her - the nightmare will end up blowing up in YOUR face, not hers if she does something even mildly incorrect (read ILLEGAL!).

I think you have made a good decision and choice.  

Need to learn about commercial lending, starting LLCs, and need to polish my math skills in relation to making good investment decisions for properties I'm evaluating.

I need to make a decision within the next 24 hours.

This is a business decision. 

I can only imagine the insight and knowledge that will come with this decision.

Then make your decisions.