Family Feud: When Cousin's Controversial Choices Strain Unconditional Support

Dear Annie: Family bonds run deep, and when someone close to you seems to be spiraling, it can be both heartbreaking and frustrating. My cousin, who has always been more like a sister to me, has been making a series of increasingly reckless decisions that have me deeply worried.
Over the past year, her life has taken a troubling turn. After the birth of her second child, she appears to be struggling with choices that not only put her own well-being at risk but potentially impact her children's lives as well. What began as occasional poor judgment has now evolved into a pattern of behavior that feels increasingly dangerous and unpredictable.
I'm torn between wanting to help her, protect her children, and respecting her autonomy as an adult. Each conversation feels like walking a tightrope - I want to offer support without seeming judgmental, to guide without controlling. The delicate balance of sisterly love and genuine concern weighs heavily on my heart.
I know she's going through something significant, but I'm unsure how to approach her without causing her to withdraw or become defensive. My greatest fear is watching her continue down this path and potentially losing the close relationship we've always shared.
What steps can I take to genuinely help her while maintaining our connection?