Señorita is already a diminutive form of señora. The ‘-ita’ replacing the ‘-a’ is roughly equivalent to the ‘-ette’ suffix that English uses in some cases (borrowed from French).
Depending on the exact context, a diminutive form like this may refer to the thing being talked about being small or in some way lesser than the normal meaning of the word, but when talking about people and animals it usually means that the person or animal being mentioned is young. For example, the Spanish ‘gatito’ is the diminutive of ‘gato’ and means the same thing as the English ‘kitten’, and similarly ‘perrito’ (the diminutive of ‘perro’) is ‘puppy’ (and yes, ‘burrito’ is also ‘little donkey’, though from what I understand that usage is uncommon outside of farming communities).
When a Spanish noun has an -ito/ita ending, the English word "little" precedes that Spanish noun's translation. Thus, if you only goal was to communicate, then the translation you propose should be accepted. However, be aware that translating "señoritas" as "young ladies" is preferable, more literal. and hence better.
I talked about this to my Spanish speaking friends. They say back in the day a girl was called "nina" or "chica" until she was old enough to marry--15 then she was called "senorita" until she got married after that of course she was called "senora". I get confused about "los hijos" too. I guess it can be "the sons" or "the children".