Marion & Ivor

My latest acquisition to my collection of old wedding photos.  I know the couple's names as on the back of the photograph is the following: Margaret bridesmaid at Marion & Ivors wedding.

Date wise I'm very unsure.  My guess is maybe the 1930's as huge wedding bouquets were very popular then and apparently pinstripe suits were very popular in the 1930's have made their way here from the US.

I'm wondering if Marion and Margaret are sisters.  Can I see a facial resemblance maybe?  I'm not sure.  I do like Margaret's hat.  Not quite so sure about Marion's.