Pup’s first heat

Sweet Miss Pixi has just begun her first heat - I found a little brown dribble this morning. She’s 7 months old. For those of you with a female WFT, how long will this first heat last? We plan to get her spayed after this and closer to 1 year of age. When did you get your wee girls spayed? Has anyone done the hormone-sparing (hysterectomy only, not ovaries) spay?