Those are interesting things that Missy does with the tree, cone, and previously to get on the couch!
That's a good idea to keep them from jumping.
Awww, poor Chelsea! Excellent idea to put the antibiotic cream on the stitch area, as well as the lidocaine.
Sometimes stitches just don't do what they should, and even when they do, they can hurt/itch.
If they stop looking like Missy's, or develop an odor, they may need systemic antibiotics. I've had that happen on occasion with a dog or cat, though a very small percent, and antibiotics from the vet always righted the situation.
Please keep us posted on how she's doing.
Love All Life, Thank You For Posting! :)