Book about two kids trying to find their mother and they walk hundreds of miles in the city

[Alex]

These two kids are looking for their mom and also their home in the city I think and they walk for a really long time and I specifically remember that they eat Vienna sausages. I read this in like 3rd grade, read to us by our teacher so it was most likely some type of kid literature although a bit older. It was NOT the box car children.

[Alex]

My friend and I genuinely feel crazy because it seems as if no one else remembers this book and we can’t find anything on Google

[Pony]

This doesn't quite fit your details, but I figured I'd give it a shot anyway, just in case: Homecoming?

Also, what year were you in 3rd grade and do you remember if the book was new or an older book at the time?

[Alex]

I don’t believe it was homecoming, and i was there 2018, I’m pretty sure it was older because I recall it being a smaller rectangle book, one that had to be read to us maybe because it was above our level

[Rainbowheart]

Cave Under the City?

[Andy Phillips]

Why are they walking around? Are they just lost, or was there some sort of disaster (war, natural disaster etc.)?

Do they stay in the same city or walk a long way across country?

Does it feel like a realistic historical setting, modern or fictional/fantasy? Do you have any idea of the location (Europe, North America etc.)?

How old are the kids? How many are there?

[Jordan Mills]

Did they go swimming in a fountain after hours to get money and rent a post office box? From The Mixed-Up Files Of Mrs. Basil E. Frankweiler by E. L. Konigsburg