Before we moved barns, Vega was being stalled next to 2 geldings, and when she was turned out, she was next to geldings as well. Though she didn't go into season much at all.
Since we moved and she's been living with geldings, she's been going into heat a lot more.
I would try and change the situtation of her being next to a stud. A friend of mine's mare went through three round pen panels (those metal ones) to get into a stud