From NYC:

Grand Central Pkwy to Van Wyck Expwy to
Belt Pkwy East to
Exit 24A (Merrick Blvd/Francis Lewis Blvd.).
Make right at light onto Brookville Blvd.
Go 3 blocks. St. Clare's is on the left.

From Long Island via Southern State Parkway:

Southern State Pkwy to Belt Pkwy West to Exit 24B (Merrick Blvd.)
Make 1st Left at light (Merrick Blvd).
Go 4 blocks. St. Clare's is on the left.

From Long Island via LIE:

LIE to Exit 30S
(Cross Island Pkwy South/Kennedy Airport) to
Exit 24B (Merrick Blvd)
Make 1st left at light (Merrick Blvd.).
Make right before light(Brookville Blvd).
Go 4 blocks. St. Clare's is on the left.

From Brooklyn:

Belt Pkwy East to Exit 24A (Merrick Blvd/Francis Lewis Blvd.)
Make right at light onto Brookville Blvd.
Go 3 blocks. St. Clare's is on the left.