Help photographing white clothing using nikon d3100?

Each time I photograph white clothing that has details such as beadwork, etc, the color washes out completely. I then lower ISO to 100' then the clothing shows a little better, but the model's face becomes extremely dark. I'm using a Nikon D3100.

It is clear that you do not understand how a light meter works

Buy an 18% gray card to measure the exposure in the manual mode and then shoot away

Shoot in Raw, slightly under expose use the EV (Exposure Value) compensation to under-expose by around 1 stop, you want to be just under the point where the white dress begins to burn out, open in the Raw Converter and adjust to taste, you can even get two different exposures on different parts of the image, but you must use Raw and there must be no blown out to white areas (hence the under exposure).

Increase exp compensation.