Voting Question: Legal question about the rights of a conservator for a minor?

I have a friend whose husband passed away. He left each of his children a portion of his life insurance, and one is a minor (17 years old.) Now the mother is going to probate court to file to become the conservator for her daughter until she becomes 18. My question is, can the mother use the time between now and when the child turns 18 to set the assets up in a trust that would keep the minor from receiving the money until she is older and more financially responsible, or is it a foregone conclusion that the money will go to the daughter when she reaches age 18? Also, how hard is it to go through probate and become a conservator, and is it long and costly process? Thanks!