What is the best electronic meat grinder?
The $500 one.
Entry level electric grinders come in at about $100+/- (I assume you mean electric - I don't know if home market grinders entered the electronic age yet).
In my opinion, they are all basically created equally lousy with plastic gears, cold metal, etc.
(two different such models crapped out on me within weeks of purchase. Today, I rely on my hand-crank)
If she's going to use it that often, get a professional one, maybe $500 or so, something like this
Twice a week works out to $5/use in a year, $2.50/use in 2 years, and so on.
If she is using it that often I would look at one of the more heavy duty units like the ones used for beef jerky. They are stand alone units , and will have motors rated for lots of grinding. This subject has been covered before, so a search of the forum should get you more on specific brands to consider.