It doesn't really mean much, it it more of just a sound people make. Sort of like あの or えと. In this case, it is sort of like a sigh, and adds emphasis, more like saying "Don't worry, it was fine". Also, the correct sentence should read like this: *** A daughter asked her mother how SHE managed to look after all of us without mod cons. *** Or it could be said like this: *** A daughter asked her mother "How did you manage to look after all of us without mod cons?" *** Do you see the difference?