With Victoria Pendleton now focusing on dancing and Jess Varnish taking a rest after the Olympics, the 20-year Welsh cyclist beat Victoria Williamson to retain her crown and will now seek a double in Sunday's keirin.
"I've never had this many people from my family come to watch. I'm so happy to have everyone here. They all sat in the front row and cried. It means a lot to me," said James, who was this week named in Great Britain's squad for the UCI World Cup in Cali next month.
"It's been a brilliant two events. I hit the targets I wanted to hit. I'm still in a big training phase and I'm looking ahead to Sunday now."
Matt Crampton, who missed out on Olympic selection, won the men's keirin title ahead of Matt Rotherham while Craig MacLean, a former Olympic silver medallist, who won gold as a pilot at the Paralympics, claimed bronze.
"I felt nervous, I had tingles all over. You really, really want it when you get up there," said Crampton.
"I've not had a great year so it's nice to top it off with a win here in an event that's so-called my favourite - it's really special."
Elsewhere, Paralympic and world champion Mark Colbourne took his second title, adding the 3km pursuit title to the 200m FS time trial he won 24 hours earlier.