Hello Beckstar1982 and Bsiggyme,
I originally suggested you may be looking for St Hilda's Middlesbrough not Eston as that was the only St Hilda's I knew of in the area. Beckstar, I rather think your mother's friends will be correct and the church you are both seeking willl be St. Helen's in Eston, a very old church in use from around 1100 until about 1962.
Have a look at Google the church is being, or has been, rebuilt at Beamish, very interesting history and pictures.
Many thanks Jomot for the St. Hilda's (Middlesbrough) links, this is the church with my family connections.
Ceeoh