There is a provider that I have been considering but she is now posting as "New girl in town" instead of under previous name.  She had good reviews and is using the same pictures.  it causes me to pause as to why would someone do this. Any thoughts on good reason to make such a change?  

Like when old time products dress themselves up in new packages plastered with "new" and "improved" on them.

I saw someone pretending to be a close friend of mine on Tryst recently. Reached out & confirmed it was not her. Approach with caution. The frauds are abundant.

A few days ago, I discovered that another provider had stolen my pictures and was using them in a different state for another agency. Luckily, I caught it quickly, and the agency removed her profile with my pictures. I find it difficult to understand such a move.

The simple explanation is because you've got great photos! ("Imitation is the sincerest form of flattery." - Charles Caleb Colton, 1820. Outright theft goes too far.)
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I think you are currently with agencies only? You might want to ask them about "watermarking" your photos or even all of their photos. YOU can also watermark your own photos before you submit them to an agency for listing (or for your personal website, if you have one). Search the Newbie board (and General) for "watermarking" and you'll get a lot more details.  
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Others will be less likely to copy and use your photos with a "Aiza" or "XYZ Agency" unobtrusively printed thereon.

Thanks a lot ☺️ You’re absolutely right about the watermark — great idea! As for me, I would never, ever in my life take someone else’s pictures. I’m glad a few people on TER informed me about those stolen pictures. This person’s self-esteem must be on the floor, not to mention that it had to be a provider using fake pictures…  

Sometimes the ladies have various security issues: Stalkers, legal issues, family members getting tipped off, etc.

I had to change my name as someone was using that information against me. I still have all my old reviews, but I take new pics every few months so my pics are gone anyway.

personally If I were you I would ask her why the name change?.
She may have a stalker whos not a TER member and its just simple to flip your name.
Ive used the same name for 20yrs so I havent but I know ppl who have
Then again it could be someone else who stole her photos Ive had many of my photos stolen and have had clients call me to tell me a chick in Oklahoma or LA is using my images
some chicks are lazy and they are con artists
She may have a BF  friend sister parent ect...whos in the dark...but not really so she changes her name to throw them off
There are a lot of reasons to change your name
Just ask her!
good luck

Hopefully this is not a case of shrinkflation, where are the quantity of product decreases in the price increases for the same thing!