Custom-made gown is too long and dress maker gave me too many problems so will not deal with her anymore. Is it essential to hem a gown with a serger machine, which no local taylor has or can a gown be hemmed with a "baby hem." Finding a dressmaker has been an ordeal from the get-go. Any suggestions will be welcome and any dressmakers in NY area who can do this?

You can hem it any way you want, so long as the fabric on the cut edge doesn't start fraying or coming apart. A very narrowed rolled hem (which can be done with a rolled hem attachment on a regular machine) would work great for something woven like chiffon or charmeuse.

For some stretch fabrics that don't ravel or fray -- like stretch velvet, some lycras and dance crepes, and slinky -- you can just cut the hem and not finish it at all.

Another idea is to cut the hem, sew 1/8" elastic (without stretching) along the cut edge on the inside, then fold the elastic up to the inside and zig-zag it all down so the cut edge doesn't come apart. This will work for wovens or stretch fabrics.

Yet another idea is to sew "horsehair" (really polyester) braid into the hem. Any dressmaker should know how to do that, it's a standard professional finishing technique. I suggest using braid that is no wider than 5/8" of an inch. Again, don't stretch the braid or the fabric while sewing it in.