The OP asked a personal question, what should she do for a person who took the time to give her child personal attention.
As for your question what wuuld happen if this became the norm of all people to ask and follow through on. I’ll tell you exactly what would happen.
1. Far more people would be involved in redding shidduchim
2. Far more shidduchim would be redd to the slighlty older girls, since all things being equal it is they and their families who are most likely to ask the question.
As and aside, Shadchanim note wirly that the people most likely to show appreciation to them for their time and effort exteneded are the LESS comfortable people (read people with less money).
It has something to do with the degree of a sense of entitlement that one feels. The greater the sense of entitlement the less they appreciate what the person redding their child a shidduch has done for them.