I then found 3 properties from wholesalers in areas that I invest in regularly and purchased the properties with a hard money loan.

It is possible to get 90% of your purchase price and 100% rehab funded as a first timer in 1-4 units.  

Single family has more stabilized as there is not enough people who can afford homes.The purchaser is two very distinct types of groups who buy MF vs. single family and single family is bought to own and occupy, MF is bought to generate money.

If your mother does not want to carry the note long term, there are GSE renovation loans that can be used for both purchase, rehab, and permanent financing all in one loan.

I frequently hear that someone purchased a new property because their real estate agent told them they could get X amount for rent, when in fact, the market comps don't support that amount.

That ensures you don't spend it on other things and know exactly how much you have to spend on the next purchase.

I have a followup question - I will realize a lot of capital gain from this home in Idaho, so I think unless I purchase a new primary residence I will have to pay that capital gains tax. 

@Moshe MarcianoI recently helped an investor from Orange County purchase a single family home here in San Diego.

First, congratulations on purchasing your first property together.

Is this for a primary purchase or build to rent/sell?