Can anyone recommend a food that is good for the
dog but comes in a size this little one will be able to handle?

I have to wonder a bit about her not being able to handle the size - my
JRT weighed 4.2 lbs when I got her, and never had any significant trouble
tackling dog biscuits, bones, and chew toys that were WAY bigger than any
piece of kibble.
However, FWIW, ProPlan - which is a good quality kibble despite being
made by Purina, and won't break the bank like the so-called "premium"
kibbles- is in small, flattish, rounded pieces which even a very small dog
ought to be able to handle.

I use Pro Plan small bites for small breed dogs. It works well for Maui.
Cali still gets what her breeder feed her since I was given a 10 pound bag
of it (its Diamond brand). I was thinking about getting the regular Pro
Plan for Maui so the bites are bigger but he doesn't like to chew so I am
thinking he'd choke trying to swallow them whole like he does with the small
ones now.




My JRT (now full grown at just under 14 lbs) has no trouble chewing it
up,
and my elder dog who doesn't chew, but swallows kibble whole never has
problems with it.
I feed the turkey-barley formula, and my dogs do extremely well on it.