Sit/stay can be a very hard one for velcro dogs. It was with Sawyer. Summer gave good advice, especially if you have the patience to take it in that micro of increments. I usually keep a slight bit of pressure on the collar when first starting this, to reinforce the idea that she is not to go anywhere. Then tell her to stay (give your signal if you have one) then slide in front of her so that you're still looking at her, but directly in front of her so that she cannot go anywhere. Only pause for a second, then return to her side so that the two of you are in the classic "heel" position, what I usually think of as "Neutral" for this exercise, and give praise/treats. I would not make it too effusive, as being calm and attentive works better here than happy and excited. Usually just a firm stroke on the head with a "good" and/or a small bit of treat.
Continue the pattern of "stay", step in front, wait a second or two, then return to neutral and light praise. Increase the distance between you and Chloe only as you feel she can handle it and won't be inclined to get up. It might take a bit, but I've seen very jumpy dogs pick up stay quite quickly with this method. As you get a couple of feet away, I begin to gently rock back and forth on my feet to get them used to the idea that even if you are moving, they still need to stay. Once they are used to this idea, then begin to gently play with the leash. Some dogs have a rock-solid stay until the moment they feel any movement or pressure on the collar, then they are moving towards you like lightening. Only add in distractions as you feel Chloe can take them! Set the dog up for success!
Good luck! and I hope this all made sense and I didn't leave out a bunch of important words.