@Michael Kattouah how is this any different than doing the exact same thing on a primary residence with a mortgage?

BECAUSE THE CITY DOES NOT ALLOW STR UNLESS THE HOME IS YOUR PRIMARY RESIDENCE!!!

.- People will fight to give everything they have to keep their primary residence, but if their second or vacation home becomes a pain in the rear, they’ll sell.

Your child will apply for conventional primary residence financing. 

I feel i’ve grown a bit fast for myself and now have secured 3 rental properties under my belt in one year - Two being out-of-state and one being my primary residence turned into a rental, which is what brought me to this question: does anyone know any real estate attorneys in Texas that can look over my lease agreement?

You can check local banks, TD Bank does do HELOC's on Investment properties (90% LTV on up to 4 investments + 1 primary last I checked).

I'm selling my primary home which has a $1700/mo income producing rental used for MTR/STR.

One should consider extensive research on both the company and the primaries. 

We're planning to move there eventually and rent out our primary in Georgia.

Purchase price: $196,000 Cash invested: $8,500 Sale price: $325,000 I bought this home as a new construction home and made it my primary residence for about 1.5 years.