Dressage is an addicting discipline...beware!
If you have a horse already there's no reason you cannot do dressage lessons on him/her. This is, unless you want to keep him/her strictly western. Two of my horses were started western, one made second level before injury and the other made fouth. So don't think you need
to invest in a "dressage" horse (unless you want to...new horses are always fun!!).
What I see off the bat is a horse with no connection to the bit. If she is truly a second level horse her connection should be much more solid and steady, in my opinion. It also appears that she doesn't track up and if she is it is barely noticable (which could be/likely is the root of her connection instability). She looks to be travelling on her forehand. I'm not sure where you are but, in Canada, the second level tests are to show the horse has begun to develop uphill tendancies, more collection onto the hindquarters, and is reliably on the bit, basically. Personally, I feel that if you were to look at her scores from the second level showing she is said to have done that you would find some fairly unimpressive scores.
She looks to be steady in her general way of going which is good. I think a lot of the things I see off the bat (tracking up, connection etc. The connection will come once she engages her hind end and uses her body better) are definitely improvable. She is super cute but as a horse that is supposed to be "second level" I feel you can find something a bit more confirmed at the level. Also, those videos aren't the best. It would be nice to see her go in a square arena. I would ask for a video about seeing her go outside of a roundpen before I went to see her.
Good luck in your dressage endeavors!