So I placed an ad on CL looking for an incall sensual massage near my area hoping for a convenient, occasional fix.

The first reply was from a girl that was close, eager, and seemed to be what I was looking for. But, she totally misunderstood the ad, was flaky, and after many useless, one line emails over 2 days, she tells me she can't host.

The second was from some battle ax that attempted to shame me for posting the ad. She's barking up the wrong tree.

And then #3. Mid 30's, articulate, was upfront, gave all the info I requested and included decent, good looking pics. Not as close to the area as I was looking for, but hey, you don't always bat 1.000. Very promising.  
It seemed that she may have used her real name so I typed it into FB. Bingo! The name and pics were a match. Only problem is that we have a mutual friend, my daughter! What are the chances?  
My daughter does not currently live in MN,  and after more digging, I couldn't find any real connection between the two except that they were friends on FB.  

The big head tells me to forget it, but I'm still on the fence depending on future emails.
Has anyone else run into this problem?

First the fact that you posted an ad yourself on cl is super gutsy. I take it you live nowhere close to the cities.

 Also just because her and your daughter are facebook friends does not mean she knows who her dad is. I don't know 90% of my friends parents and they don't know me or my name. Just don't use your real name, go meet her, have fun, and she would never even know who you were. If you have never met her through your daughter I am sure she has never met you. We all have secret lives when we do this - even the ladies.

It hasn't happened to me (I met a SB who went to the same high school I did, but decades apart.)  But I always thought, what if I meet a cousin or something.  Then I thought, cool.  

The more communication there is between this girl and your daughter, the riskier it becomes to see her.

Yes, wouldn't it be cool to meet your cousin when looking for a provider? I guess I don't swing that way.

I enjoy a tug from a hottie now and again, in addition to the full service appointments.  This happened 10 or 15 years ago (I have been mongering since the days of Lee Lenore's on Snelling).

I made an appointment to see a new to me rub and tug lady in St Paul (a place I tend to avoid, due to the mugshots they post), and after the first 5 minutes, it became apparent that the lady was... my friend's MOM!  She didn't recognize me, but I couldn't continue, tipped her, and bailed.

Now, this mom's other daughter lives in town, and I always keep my eyes peeled for an ad from the daughter, (my friend's sister), because she's smoking hot, and I would love to watch her tease a load out of me.

You don't know this person.  Sounds like she is not a pro and the boundaries between you and her are not going to be well defined.  In similar circumstances, with a well-established professional, I might take the risk.  But this woman could be totally bonkers for all you know, and if the connection ever came to light, it could be big trouble.  You have no control over what she might do.  There are loads of professionals who will protect your privacy and theirs.  Don't risk it.

In my case, I had been seeing a massage provider off and on for a few years when I discovered that she was a friend of my wife's sister. I found out because she commented on one of my sister-in-law's Facebook posts and I recognized her from her profile picture. From her comment, it was clear that they were IRL (not just FB) friends.

I've had some mixed feelings about seeing her after the fact. I haven't let on that I know that she knows my sister-in-law. For all I know, she might have recognized me as well from my comments on my sister-in-law's posts (it goes both ways, right?). And, if I'm being honest, this kind of makes it hotter for me -- both the not knowing if she secretly knows who I am, and the seeing someone who is connected to my in-laws.

I'm a little nervous that I'll bump into her at a family function. But she's definitely one of my top two favorite providers, so I've seen her a few times after that.

Man, there are tons of options, send me a PM!