she later helped found Lucy Cavendish College 这句话的helped found是不是help do sth 有这用法?

是的.
这个found是vt.创办,成立,建立的意思
她后来参与创立了露西卡文迪什学院那这句话不就有两个动词了？help to do sth 可以省略 to ，就是help do sthshe later helped found Lucy Cavendish College，----，she was an honorary fellow. A since then B after that C of which D from then on哪个才是答案呀C of which这样是宾语从句如果是选其他，就成了两句话了，不应该用逗号了。