Marinette was determined that she was going to get her brother a female to reproduce with. Her brother was a slave in her pride, but she was not, and she was determined to find a willing female for him to have cubs with. If she could arrange everything right, perhaps her brother would get to keep a dark cub to raise. She really did not want him to get a light cub since that would just be another slave. As much as she loved her brother, she certainly did not want to cause his offspring to be slaves anymore than she wanted her own to be. If she could have convinced her brother to leave, Mari would have done so, but she really did not think it was practical to try right now. Two things stopped her, one being their father still living and the second being her brother's lack of desire to change things. He seemed truly happy with his life so long as he was with Mari, so perhaps the best thing would just be to take him as her own slave once their father was gone. It would not be so bad to put up with the pride and it's strangeness to help her brother. The demoness certainly wouldn't abandon him.
Strawberri Stardust
sorry this took so long RL and muse stubbornness.