Who hasn't had a TER review in three years?  Two reviews, 2016 and 2018.  Both good reviews.  Seems sweet, very accommodating.

who she is and where.....

LLAP,
Swim

Can a provider trust a monger who hasn't written a review in three years?  The answer to both is . . .  it depends on what other factors there are.  I think you have to assess each situation on its own individual merits.  Its hard to have a one-size-fits-all solution with interpersonal relationships.  

Your OP doesn't have enough information.  
Does she have recent ads, an up to date website,  Twitter,  etc...?

Are the two reviews from mongers with a  history of consistent reviews?

and of course,  what do you mean by trust?

Providers get fat, get older, change their menu,  but generally don't turn into robs. Generally.

I wouldn’t do it! Too many fresh faces with new photos and plenty of reviews to rely on! You’re asking for disappointment!

Nikki Nix in Dallas

For the record, Nikki Nix's last logon on P411 was 11 days ago on July 2, 2021.

but based on the two reviews that she does have I would trust that she is "legit".

 
That said,  A lot can happen in a few short years both in appearance and attitude. One suggestion I might make is to PM her reviewers, one of them in particular, NevertooLarge, is very active on the boards and he might be able to give you some of the insights you are looking for.

Personally I consider those reviews as being too old to be reliable. Who knows what’s happened since then in terms of weight, general appearance, quality of service, personality, etc.  

A review, even when accurate, is nothing more than a snapshot of what a provider did with a specific person during a specific time. Ideally when deciding to see a girl I prefer reading lots of reviews or mentions to help get a better idea of what to expect. At the very least I’d like a couple recent reviews or comments from people with an established history of providing reliable info.

For me 2 reviews from 5 and 3 years ago really doesn’t cut it. I’d at least search for other reviews on other websites, or if anyone’s made any recent comments about her on other forums. Maybe she’s on Twitter or some other social media platform.

Ultimately though if you really want her you could just throw the dice and send her a text or email. There’s no harm in at least asking about her rates, availability, and any potential screening info.