Management: Put everything away that you don’t want your dog to get and only remove things from them if you absolutely have to (e.g. if they are a danger to her). Reducing conflict with you will help reduce their resource guarding.
Making your approach a happy event: When your pup has a toy, calmly approach and when you get near them, toss a treat towards them, then just walk away again. Repeat. You are teaching them that your approach means that good things are going to happen, not bad. Only approach as close as your pup is comfortable (if they stiffen, hunch, rapidly pick up the toy, growl or snap you are too close). With practice, the distance from you at which they are comfortable will reduce and you can get closer to them to drop the treat.