I did just realize this is for August and Reiner's partners. But I still wanted to share the idea. If she is used for Reiner's partner, the last name would be Viremont-Wolfson (IDK how to spell his last name).
They met while Stirling was taking down a corrupt leader or while she was helping a few soldiers with their PTSD and guilt. Their kids are twins (teens), Emelia Viremont-Wolfson and a son named in honor of Reiner's father. Their youngest is 3 and is Havean Viremont-Wolfson (adopted)
Note: Stirling's background and persona stays the same. Only difference is that in this case, she allows people to call her Diana.