I had a stepmother in the 1970s before it was a normal thing.
Only myself and one other kid in my year (and we were at a 7 form entry comp) had a step parent. FWIW, neither of us were happy.
Although that was bad circumstances maybe as in both our cases, our real parent had died so we werent just step kids cos of divorce, with 2 parents alive and kicking somewhere in the world.
My stepmum was, as it turned out, mentally ill. She starved me, neglected me, bought things for her own kids and not for me, and by the time I was doing A Levels I had to hand wash all my own clothes whilst she washed her's and her daughters' in the washing machine. If she knew I had an important exam, she'd pick an argument with me before I went to school. Once or twice, when dad wasn't around, she put her face right in mine and screamed abuse. Never in front of him. She'd feed us tiny meals and then cook a second, proper sized tea for my dad and her older, working daughters. My stepsisters had a load of insurance money from their dad dying, so if they were hungry - they went down the shops. I had nothing.
My clothes had holes in. (They could buy whatever they wanted). And by the time I left that house, aged 19, and five foot six I weighed 6 1/2 stone.
I don't have a very positive view of stepfamilies.
Years on and my husband is stepdad to my two youngest kids. I never thought I'd ever get in this kind of situation, myself. But I did. Their birth dad is a Fathers 4 Justice looney and totally has nothing to do with them. Their step dad is in every respect, their dad. He loves them, cares for them, looks after them if they're sick in the night, helps them with homework and has never treated them differently to our own kids.
Know what? After all that - I still hate step families. I had to forgive my stepmum as if she was mentally ill then it wasn't her fault. But she was a dick. And to a motherless child? Not right.
But I dislike her and now she has senile dementia, I don't let my kids see her.