Agree that a basic leash would be fine especially if you train her well (no, not like Max!)....you may not need a harness unless she tries to run ahead then a harness will protect her neck. We like the Truelove brand of harnesses and collars...and they come with reflectors built in if you walk her at night.
I love harnesses for my small dogs. Their necks are so small and usually their windpipes are pretty close to the surface, so they can be injured pretty easily if pulling. We use the truelove harness with the reflectors for our 12 pound chiweenie and love it.
Our dog also wears a harness. He was a very tiny puppy, and the pet store recommended a harness to protect his windpipe. He also is a bit (a lot) of a chicken, and tends to run at the sounds from trucks pulling trailers. He can’t bolt out of the harness, as he did one time with a regular collar. We have a Rabbitgoo brand harness and it is an easy on/off. And please, more pics of that sweet face!!
I would 100% go with a Wonder Walker. It is comfy for the dog and helps them resist pulling. I have a 15# chihuahua mix, but we've been using the WW since he was half this size. My friend with a larger dog also uses the Wonder Walker. They come in all sizes. Extra super cool bonus - MADE IN SEATTLE. You can't go wrong!