I have recently found a great property to put under contract (excellent), the owner is very motivated in getting the property off her hands, she has a buyer in mind who wants the property(her sister)  and even agreed to lower the offer I originally gave her (sounds like an easy sale right).

It's great motivation. 

How can I structure a deal that the seller is very motivated but owes $128, arv $150k, and needs $5k to move into assisted living?

As far as appreciation is concerned Memphis is still a Buy and Hold Play the appreciation is not even close to what you will achieve in the Western States.

Check out the forums under Starting Out, you'd get a lot of tips and motivation from investors who got over their fear.

I bet the first deal stands out in an investor's mind, but what is one achievement, directly or indirectly, related to REI that you feel is your greatest achievement or the one you are most proud of.

The four-mortgage mark may well be where I turn the corner and pay the first property off, so the financing remains achievable through conventional means. 

Congrats and keep focused, you'll achieve your goals.

When I worked with the public, the first question I asked was "tell me about your situation" because if there wasn't a motivating factor in that answer I was off the phone in under a minute. 

One of the biggest questions I have is once I find a property that has the signs of a motivated seller, how do I find out who the owner is?