Asked to Borrow Money

I was recently asked to borrow $2,800 by someone I used to be friends with. She and I just started talking about 6 months ago. I've known her for 27 years, and I thought we were friends. There were many scenarios that happened over the past 10 years that made me rethink our friendship and decide that she's really not the type of person I want to hang around. There were several smaller offenses that I ignored or chalked up to it being bad timing and what not. The final straw for me was when my mom suddenly passed 3 yrs ago, and she called to "check on me," but started to immediately complain about her job and how all of her co-workers were jealous of her. In my time of need, she wasn't dependable and was nowhere to be found. And when I did hear from her, she only talked about herself. So I slowly stopped calling, and missed a phone call or two and that was the end of it. I heard from mutual friends that she was upset w/ me and felt that I wasn't there for her when she was going through a crisis-breaking up w/ her then boyfriend and how I was selfish because I was acting like I was the only person hurting or dealing w/ a crisis. I had tried to reach out to her to discuss the issue, but she wouldn't answer or call me back. I gave up because between my mom passing, her asking me to borrow money 5 days before my wedding, and all the drama she caused at my wedding between herself and the other bridesmaids, I had had enough. So 6 mos. ago, I heard her grandmother had passed. I reached out to her to offer my condolences. We then ran into each other at church (she moved away years ago and lives in another state) over the summer, and at a mutual friend's BBQ and she was super talkative and acted like nothing had ever happened. Since then she's been reaching out more. So today she texted me and the conversation was pretty normal; how are you? How was your holiday? She tells me she's flying out tomorrow to go see her boyfriend who lives in another state. Then an hr later, I get a very long text message and she asks me if I can loan her $3,500 and that she'll pay me back over the next 6-12 months and make monthly payments. She stated that it's an emergency and she's knows it's a lot considering all we've been through. My initial reaction is no and my gut says no. It has nothing to do w/ what we've been through, but lending money doesn't make for a friendship in my opinion and I'm not a bank. I don't have $3,500 that I can give away because when you lend money, you have to be prepared to not receive any of it back. Now if I'm going off of past history, in our 20s, I lended her $1,500 over the course of a year or two, and never received a dime back. When I was down on my luck and out of work, she never offered any assistance or attempted to pay me back. So our past interactions make me want to say absolutely not. I think I'm so uncomfortable w/ the request because of our relationship now. I don't consider her a friend, and don't feel obligated to stick my neck out. I'm also uncomfortable because she asked me via text message. I know we're in the age of texting and DM'ing each other, but I don't feel that it's appropriate given the nature of what she's asking. If it's such an emergency, pick up the phone and call. Not sure how to handle this situation. And it's a little fragile/delicate given our broken relationship.