legally, but it's good marketing for those who think that such a disclaimer means she can't possibly be LE if she's posting this. Legally it's no different than a "No Trespassing" sign in front of a meth lab. Or, more pertinently, asking a client if he's LE or affiliated with LE.
There's NO WAY it would ever hold up in court, probably only be used against you!
I have heard of LE going so far as getting head before making an arrest, so it's pretty safe to say that NOTHING is going to help you!! This provider about the head story DID get her charges dropped, but still was arrested and detained.
I was told several times by many people NOT to even put that disclaimer up, just because it IS pointless.
Also, asking someone if they're a cop also doesn't work, they can and will lie about that!
In Florida, the LE doing this stuff HAS to have an out of town number. So if shes in Orlando with a Tampa area code, question her about Tampa! That usually throws up red flags because if they don't know the main streets/highways, they're clearly up to something! Also, cops (in Florida) can NOT come down to the car to get you or meet you for drinks. So if you ever feel sketchy, just ask her to come greet you in the hotel lobby, out the back door, or at your car.
Be safe and have fun all!