I personally would get her spayed as soon as possible. I have heard that if they go into heat their disposition will change & they can become more aggressive & if you get them spayed after that then it doesn't help their aggression at all. If you do get her spayed before her first time going into heat, then there's a really good chance that her disposition won't change. Ask your vet if it is at all possible to take her home with you after she has the procedure done. I know that some people here on YT have asked their vets if they could take their furbby home & monitor them themselves because they know their dog the best, & their vet agreed that they could take them home. It wouldn't hurt to ask & your vet might say yes, so it's worth a shot!
Amy