Hi, I live in Crestwood, so hopefully I can give you some insight into the area. Crestwood & St. Vlads are in the City of Yonkers. It is a very nice area and I absolutely love living here. Even though we are part of the City of Yonkers, it is like living in a small town. East of St. Vlads, we have the Crestwood library, a metro north railroad station that will take you into Grand Central Station in Manhattan in 30 minutes, the Bronx River Parkway which will take you south to the Bronx and Manhattan or North to White Plains and northern Westchester. In the spring and fall the Parkway is closed on Sunday mornings for Bicycle Sundays! We have a cute town with a pizzeria, dry cleaning, shoe repair, barber, hair salon, bank, restaurants, etc. West of St. Vlads is Central Avenue which is a major shopping strip with lots of name brand national stores. All a few minutes drive from St. Valds. Yonkers public schools do not have a reputation for being the greatest (usually at the hs level), but we do have a great public school in the neighborhood PS15 that I believe will be going pre-k through 8th grade soon if not already (it was pre-k to 6th grade but they are adding a grade every year). Most families in this area send their children to Annunciation school for grammar school and the Annunciation church is major social center of the community. St. Vlad's is down the street from Annunciation off St. Eleanora's and Scarsdale Road. Across from Annunciation is Schultze field, a very nice park (although there is a lot of construction going on there now & it is hard to get down the street) with little league fields, tennis courts and a play area for children. The local sports club is the Hillcrest Lakers and children play softball, little league, lacrosse, basketball, etc. through this club. An interesting website to look at is the Crestwood Historic society at mycrestwood.org
Here's an old article from the NY Times about the area:
If You're Thinking of Living In/Crestwood, N.Y.; Yonkers Area With Small-Town Feeling - New York Times
These urls aren't posting right but if you cut & paste & delte the space between B and 63 at the end of the address, it will open. Otherwise, just google, "if you're thinking of living in Crestwood" and "Crestwood Historic Society".
Anyway, back to your original question. You literally can work in any hospital in Manhattan or Westchester from this location. If you want to drive, Manhattan probably would not be your best choice due to parking in the city & traffic, but I do have a friend who is an RN and drives to upper Manhattan to Columbia Presbyterian hospital. Manhattan is a quick ride on Metro North, so you can pick any top hospital in NYC. I am not a nurse so I cannot rate local OB units, but the two closest hospitals to look at would be White Plains Hospital Center and Lawrence Hospital. White Plains Hospital (has a reputation for a great OB unit per expectant mothers), Lawrence Hospital in Bronxville (this will literally be a 4 minute drive from St. Vlads - lots of local women us this ob unit, but I'm hearing more & more about them going to White Plains.). White Plains is a new maternity facility with LDRP rooms that are compared to hotel suites. They also have a very extensive NICU.
I had my children at Weiler hospital (used to be called Albert Einstein hospital) in the Bronx. This is a very nice area of the Bronx (don't believe everything your hear about the Bronx - there are many nice, safe areas there) and would be a 10-15 minute drive from St. Vlads. This hopsital has a great reputation for patient care.
I believe Greenwich Hospital in Greenich, CT may be another hospital to look into though it would be a longer commute from Crestwood. And St. John's Riverside in Yonkers, I believe, has a new unit - but I'm not sure.
Good luck. Hope this helped.