Does Anyone Remember This Children's Movie About Trolls?

Okay, Here are the details:

1. The girl is watched over by her omnipresent Nanny who's always telling her not to do something

2. A little grey kitten/cat leads her to a little door, somewhere hidden around the mansion, and it lights up. Inside is a woman-spirit that tells the girl that she's her guardian angel or something. She then gives her a ring that gives way to a gold, half-way invisible thread. The lady then tells the girl that she will always find her way back to her home with it.

3. There are trolls who live underneath her house/town that are building homes and flooding water banks (?). They wear stone shoes, and have a very sensitive big toe. There is a mean troll queen who bosses her son around. The trolls kidnap a human boy, and they called him 'soft-skin or something of that concept.

4. The Trolls' feet are their ultimate weakness. The queen wears her stone shoes to bead, always. And, in the end, to get away from the queen, the girl and boy have to break her shoes and step on her feet.

5. At the end of the movie, there is a big flood scene. The girl's name is something like Heidi, Gretchen, Sarah, or something like that.