Who are the women that resemble amish/mennonites?

They could be:

1.There are Amish-Mennonites, whose women wear cape dresses and a plain white cover over their hair, but whose men wear relatively modern shop bought clothes.Heres a photo: http://www.beachyam.org/yfm09.jpg

2.There are the FLDS women whose men dress always in a white shirt and black trousers and whose women wear long sleeved, patterned praire style dresses and have their hair puffed up at the front and in plaits.The women however do not cover their heads.Heres a photo: http://blogs.sltrib.com/plurallife/uploaded_images...

3.There are Pentcostal 'types' who wear what americans call jumpers and denims skirts.Such groups like this are often home churches.Heres a photo:http://veiledglory.files.wordpress.com/2008/04/win...

4.Brethren women wear long denim skirts and a black triange covering with their uncut hair hanging down.The Brethren men wear a shirt usually.

5.Hutterite women wear either plain black or pokka dotted scarfs, a patterned top over a white, short sleeved blouse and a patterned skirt.Hutterite men wear cowboy hats or cyclindar style hats, shirts and denim jeans.http://www.flickr.com/photos/tseandwyer/205322742/

There are many types of Amish and Mennonites, some of whom don't get as much press as others. Some of these that don't attract as much tourist and press attention wear clothing that is mainstream or pretty close, especially the men. Beachy Amish men, for example, very often wear mainstream clothing, while many of the women still wear cape dresses and headcoverings (either veils or caps). See http://www.beachyam.org/general.htm for some explanation and pictures.

There are plenty of other Amish, Mennonite, and Amish Mennonite groups with varying degrees of plain dress; there are also Orthodox Jews and other plain Christians, but we would need more details about their way of dressing to be able to take a reasonable guess at what group you're talking about.

The most reliable way to get an answer is simply to ask them.

maybe there from the deep south or something or some type of convent... they usually have the men do whatever they like and all the women wearing a certain specific clothing and hair has to be a certain way and stuff.

Those polygamy people. They wear homemade dresses and men are "normal." A bit sexist, isn't it?

Might be Brethren. They are very modest as you have described, but pretty much normal in all other ways.