Saya was a complete idiot in this arch. Her stupid tantrum put herself and the children at risk for no benefit at all. Whenever she ended up, she would require funding for a noble, and she should know that. Having the opportunity of having such funding from someone you know is much preferred than trusting some random noble whose intentions are unknown (a complete gamble)
Also, what the heck does Touya mean by not wanting more ties by managing the orphanages? He's already tied to the brim, and he should start to see things as they are: he's a powerful person with reasonable influence. Or does he ties himself with somewhere he wishes to be tied to, or he'll eventually be forced to, and the outcome might be worse. If not tied, he may become a liability to be disposed of. A marriage would be the most effective way to tie himself and guarantee some level of trust, but assuming responsibilities within the kingdom would already be a good ideia