If you were to marry someone na may mga anak sa unang relationship what can/should you do to protect yourself & your child?

Problem/Goal: I've always wondered anong safety measures or mga decision na hindi maglalagay samin ng mga magiging anak namin once I choose to marry my partner of 2 years and a half.

May mga scenario ba na pwede kong ikapahamak or worst case scenario sa ganitong setup? I'm not really familiar with both sa law and mga rights.

Kung meron man, I hope you could share with me kung ano yun and kung mga safety measures kayo or tips na maibibigay sakin?

Context: May 3 kids yung partner ko sa previous relationship niya. His family isn't the best people na makakasalamuha mo, and they seem to have something with his kids.

Sa 2 years and a half namin, parang nagkaroon nalang ako ng kutob na pwedeng pwede ako i-throw under the bus ng mga toh.

Tapos notice ko din, yung partner ko medyo mabilis maniwala or mabilog ng family niya and I dunno, natatakot ako at baka mangialam sa marriage namin. I grew up with a broken family, ayoko yung mga anak ko ma experience yung ganon. I just want to protect myself and my kids.

So, any advice and tips are greatly appreciated. And just being wise generally.

Kung yung mga millionaires nga eh nagpapa prenuptial to protect their assets and money, I don't think it's far fetched for a woman who will marry into a family like this and to someone na may mga anak na sa past relationship.

TIA po!