
Could be too much too soon. My vet also does invisible mending, and one girl seemed as if she hadn't had surgery at all. I literally had to restrain her by crating, or she would have run a marathon. I was putting her in the crate for an hour 4 times a day. I felt awful doing it, but, apart from nailing her feet to the ground, it was the only way to restrict her.
I once had internal stitches break down at the end of the incision, but it was nowhere near as soon as your girl. Although I would say keep an eye on it, making sure any discharge is clear and not infected, just restrain her more. I fully appreciate how difficult that is, but it's the only way to go. You need eyes in the back of your head! :-)
Good Luck!