That is awesome. Things will all work out in the long run and it seems they are doing that already. I do believe that spaying both would be the best option also. When females come into heat they do tend to get "crabby" and try to compete with each other. That is when most of the disagreements happen with my girls. Just a suggestion though, plus heats can be very messy and most doggy daycares do not allow females in season during that time. Good luck with the girls and you seem to be an awesome mom!!!