It’s a very quick commute on the 4 or 5 express train. 86th and Lex to Grand Central, two stops. She can commute with me! 
Plenty of grocery stores in this neighborhood and places to eat out. Whole Foods on 3rd and 88th, Fairway on 86th, Gristedes 89th and Lex, other small bodegas. Highly recommend a walk home through Central Park, express buses on Madison are great.