Eye think eye've narrowed it down :3
So, in conclusion, either one (or all) can be the mothers
1. Reimu
2. Marisa
3. Rumia
4. Mokou
5. Utsuho
6. Letty
7. Flandre (This one hurt the most...)
8. Suika (Eye blame her juice)
⑨. Suwako
Eye'm gonna thank Rumia for jogging me memory