I don’t think there was anything wrong with your original advice, and no where did you imply that your daughter was a mistake.
The only thing you did was connect the choices made with the brutal consequences. Today, few children are prepared to hear about painful truths or difficult trade offs.
My own advice to young adults about parenthood is that with a committed partner who takes equal responsibility for parenting, it’s manageable.
If you end up trying to parent alone, it’s a years long nightmare.
Partner first, kids second.