Nope. Not in your case. Not in most people's cases tbh. This fb post sums up step
Mother life
I now pronounce you man and wife. Oh! And here’s a child that you didn’t create but you have to treat it like your own.
You must keep them properly clothed, feed them adequately, and you are in charge of their overall well-being every day that they with you. Their life is literally in your hands.
Except... you can’t be involved with the ACTUAL raising decisions. That’s up to your husband and some other woman that now dictates what happens in your house and your daily life.
So, to be clear, you have no say in their health decisions, extracurricular activities, or religion. It’s totally overstepping to provide your input on that.
But do make sure you’re wiping their bottoms after they poop and going behind them to brush their teeth properly every night, because, essentially, you are now a mom. Congrats!
BUT also you should probably try to avoid disciplining them. Leave that up to the husband when he’s home. You don’t want to be seen as the evil step-mom, do you? Do your best to present yourself as the fun-loving “aunt” in the situation.
But unlike their aunt, you definitely need to make sure that their school work is taken care of. It would look bad on your family unit if they should fall behind in academics. That’s actually grounds for losing visitation time with them.
So - just one more thing - you’ll need to try to be amicable with your new husband’s ex. You will be seeing her at least once a week and in some cases multiple times a week. She and your husband will and should have regular conversations via phone calls, email, and texts. These conversations are really none of your business but they’ll effect how you live your day-to-day. If she’s high-conflict you’ll probably spend months of your life preparing for multiple and very stressful court trials throughout your marriage. It’s all just part of your new “gig”.
I know this is a lot. Just take one day at a time. And remember, when you said “I do” just now, you knew what you were getting yourself into. You knew he had kids.
No pressure.
I would also add-
If he does agree to have kids with you, his income will always be hugely cut into by three lots of child maintenance which means less for your own kids.
Run fast very fast girl