I'm familiar with that usage, but I always thought that "frequenting" a place made the phrase, "a lot" redundant.
"I'm a regular frequenter ..." would be tolerable since, "regular" refers to some possible schedule, right?
You're saying that her expression is acceptable as it was posted? OK, so does that mean I'm being old fashioned or New Age with my paranoia of redundancy?
... or just smply, 'merican?