Spending the rest of your life with someone takes more than just loving them. A lot of other factors like emotional compatibility, personal preferences, and of course, whether they have kids or not have to before once should get married.
Some of the existing factors might be tolerated, while others are considered intolerable by other people. Like the kids for instance, many people might not be too open to settling down with someone who has kids from a past relationship.
This is because the they believe the kids represent a reminder of the person's past life, and how connected they are to their former lover. Or they just do not want to share the spouse with the child of a past lover.
A lot of other people also, do not mind settling down with someone who has kids from their last lover as they believe it makes no difference at all in their relationship.
Can you marry someone who has kids from a past relationship? Let's see what people say about this.