Katie Holmes reportedly found sending Suri off for her first day of school "gut-wrenching".

The actress' six-year-old daughter with Tom Cruise recently began at Avenues School in New York City.

Katie and Tom split earlier this year, with Suri's education said to be one of the things they disagreed about. While Tom wanted her to go to a Scientology learning facility, Katie was adamant she should attend a regular establishment.

"Having to wave Suri off after all that they've been through recently was gut-wrenching," a source told British magazine Grazia.

"Katie was in tears when she dropped Suri off. It marked the end of her battle with Tom."

Tom wasn't there to see his daughter go through the gates on her first day. He has been shooting a movie in London, UK, but Katie apparently requested he wasn't there to make things easier for Suri.

"Katie knew there would be a circus that morning, so she asked Tom not to come," the insider said. "She wanted to make sure Suri felt as confident as possible on her first day."