The 22-year-old, who had her first kiss with Underwood, revealed to PEOPLE that she and Cassie Randolph are friends from their college years at the Biola University, a Christian college in Los Angeles.
“I walk into the mansion and my friend Cassie is there,” Martin says of not knowing Randolph, 23, had signed on until the first night. “She walked in and we were like, ‘Heather?’ ‘Cassie?’ It was so crazy. I had no idea.”
Despite the fact that they were competing over the same guy, both women said there wasn’t any negativity.
“It’s comforting, actually,” Martin says. “You’re in this high-pressure situation and there is so much going on, so having that little piece of comfort put me at ease.”
Adds Randolph, who is in the final four and will welcome Underwood to her hometown next week: “Heather and I have a lot in common. We have similar values and beliefs. Having her there is a little bit like home.”
The Bachelor airs Mondays at 8 p.m. ET on ABC.