I want your opinion

So, I have a best friend. We’ve been super close for 20 years, basically grew up together. But ever since she got a boyfriend a couple of months ago, things have been completely different between us. We used to send long, enthusiastic texts and talk about literally everything—and she was always the one to text first. Now? I’m always the one reaching out, trying to keep the conversation going, and her replies are just dry. Even when we hang out, she’s literally on the phone with him 24/7, and I’m just sitting there feeling completely left out.
To make things worse, I heard some sketchy stuff about her boyfriend from his former coworkers—not even from her. Turns out he’s divorced with a kid, and one coworker literally told me he only liked my friend because she looks like his ex-wife... I was honestly speechless. On top of that, my mom recently told me that my friend is thinking about marrying him.
She literally just turned 20. I know it’s her life and her choice, but I’m genuinely worried. He doesn't have a job, barely puts any effort into taking her out, and she’s not working either—she still relies on her parents. I really want to talk to her about this, but I’m terrified it’ll ruin our friendship, especially since she’s my only friend. Am I overstepping here?