I don't know about this, but it looks a little OP to me. Maybe it should cost 2? since it only triggers when you access at least 2 cards during the run, you always get 3+ accesses. Take for example R&D Interface, which costs 4 to install. that one is perfectly balanced. This on the other hand, costs only 1 provided you are already getting extra accesses. Also it's only 1 influence, meaning you can import it into other decks easily. R&D Interface is 2 influence and is balanced.
In my opinion, this would be fine at 2 install cost and MAYBE 2 influence.
R&D Interface is form 2013, balance was different back than. Mary da Silva is balanced out mostly by how limited all the other multi-access option are you can combine it with.
— Krams
Update: It's fine as is. Well balanced!
— DDDydra