I have thought of this question, albeit not for a scandalous reason. I had wondered what would Daisy's life been like had she not gotten kidnapped and she had been forced to live out a "normal" (at least from our perspective) life. Would she have fallen in love and had kids?
Realistically, of course, inter-species reproduction would be impossible, but given the overall tone of the movie, it wouldn't surprise me if humans and Dinohattans were compatible in the reproductive department. Convergent evolution only goes so far in explaining the extreme similarities between the two species, and given that this is a kids movie from the 90s, they wouldn't pair two characters together unless there was at least the possibility of a happily ever after (marriage, kids, etc).
I always presumed that even if the kidnappings hadn't happened, she would have come across Luigi and the two of the would have fallen for each other. Presumably, they get married, and while she may worry she may never be able to have children (she knows she never had a menstrual cycle, but of course, was too scared to ever find out why). After years, Daisy then goes to an OB-GYN after experiencing some abdominal discomfort, and then the truth is discovered...not only does she not have a a cervix or a uterus, she's actually forming a calcified egg. She's horrified and worried she and her eggmight be a "monster," but the OB-GYN, despite taking a few pictures for posterity, does not decide to go to the media with this discovery and instead decides to keep the secret. Luigi and he stands by his wife.
Daisy lays the egg, and she and Luigi do all the things that you would do for a bird egg, some of which does come instinctively for Daisy. They might even go to that orphanage and get the egg container or whatever. The hatches and out comes a healthy baby boy. The OB-GYN corroborates the story of a "home delivery."
Presumably there would be future pregnancies, but I'd suspect since they know what's happening in subsequent conceptions, they're more careful and might even skip town when they know she's going to lay the egg. Blood tests will confirm the paternity and maternity of the kids. Although there'd be some uncertainty of how they'd turn out, I presume that the children would be human in expression rather than Dinohattan, as I'll assume that the Dinohattan traits will be recessive and dormant (maybe they'll have something small like long tongues as the only dominant trait). Without any other Dinohattans in the area, the kids grow up and live normal lives --although I could imagine Daisy having a girl and freak out when her daughter goes through her first cycle. The kids themselves are only vaguely aware of the family secret. Daisy eventually becomes a grandmother, Luigi a grandfather, then they become great-grandparents and live out fairly long lives (and successful ones after Scapelli's empire melts down once their bad business practices come to light).
Then when Daisy and Luigi are both old and gray, the portal between the two worlds weakens even further, allowing an old-geezer Koopa to lead the army into our world and take over it.
