Not a groomer, sorry. But I have a spayed girl too. Her coat went from short and shiny to long, soft and fuzzy. It gets matted really easily and is more or less impossible to handstrip. Even if I do handstrip her it is not as shiny as it was, and she is very uncomfortable when I do it so I stopped. But she is still gorgeous, as is yours
With a sporty clip she looks great in my opinion. We just keep some of the feathering on the legs and tail and the outside of her ears long. The rest is clipped. Not the same as natural sleek coat I know, but much easier to keep and looks good. It's not wiry at all and I've been clipping her for years now. It's still the softest, fluffiest fur I've ever felt
It's a good idea to take control of the weight now before she gets overweight. Time to start measuring up the daily ration if you don't allready. My girl started gaining weight too, but a few changes to the diet and routines and it was easy to keep her fit
If she is on kibble then the vets sell really good low calorie feeds to keep the weight off while still ensuring balanced micronutrition. It usually has a little more fibre too to keep the dog feeling full on fewer calories.
Treats can come from the daily food ration or carrots, cucumber, or other low calorie yummies. Some meat, but remember they are very efficient at utilizing proteins so not too much. Definitely stay away from fatty or sugary treats:) I remember feeling a little disappointed at all the changes, but you get used to the fluffiness and the food restrictions.