Walking around Tijuana you can find a lot of signs of poverty and first of all you can find beggars but not in Avenida Revolucion (main street of Tijuana) - it's forbidden there, I suppose.
But when you go a few hundreds meters away (on main, crowded streets) you can find them even lying on a walkway with a hat for money. Hmm... I wanted to take a picture of this one on my picture too fast :-((( ---> sorry for poor quality and... do not follow my way of taking fast pictures hehe.
There's a lot of poverty in Mexico so it's not unusual to find small kids and their mothers begging for $$ or trying to sell chewing gum, jewelry or other knick-knacks.