One of the things most Christians seem to have trouble separating, not just in wider Christian culture but also in various manosphere circles, is that vetting and preferences for marriage are different than how you should treat someone as a fellow Christian.
Marriage is a covenant and supposed to be permanent in God’s eyes. You should be selective on someone who you are making a lifelong covenant with. You want a true Christian (not in name only; who walks the walk), hopefully whose mission is aligned with yours, who is grounded with good character and morals, wants to follow God’s biblical roles and responsibilities, and ideally the least baggage as possible. More on past posts on vetting.
This does not mean those who don’t meet your criteria (whatever they are) are not good Christians or evil in some way. Everyone has sins in their past that they can repent to God and be forgiven. As Christians, we do not need to shame them or make them feel unwelcome once they are in God’s family. We should celebrate and be joyful.
But that does not necessarily mean you need to eliminate different past sins as criteria for who you want to be married. I don’t have anything against non-virgins or single mothers who have repented and are in Christ. In fact, I rejoice with them, but I also wouldn’t marry one. Same with alcoholics, other various addictions, and even murderers (heck, Saul/Paul was one before he was converted).
If you want to marry a single mother that’s great too. I know some men who have and they have godly marriages. However, it is true that it is riskier. It is one that I personally refused having reviewed all of the relevant data. Each man should pray, get wise counsel, and evaluate the risk for himself. If he is satisfied that she is truly repentant and has godly character then who am I to judge? I’ll encourage him and try to help him in his marriage.
Whatever preferences or criteria you have for marriage are fine. One can say some may be unrealistic (as in the case of evangelical american princesses). One could say some are unwise or unfeasible. One should evaluate whether different preferences and criteria are worth having or if they weed out too many otherwise good candidates. However, I don’t think anyone should have any shame for their criteria or preferences for marriage. If you’re a Christian it’s a lifelong thing and you want to make a good choice if you’re not going to stay celibate for life.
Each to his own with no shame, but it is good to be in the Scriptures, praying, and wise about your own preferences and about who you potentially choose to marry including their past.