If a person is on OPT and he got marry in UAS with H1B holder and because of company problem the H1B person got layoff from job. So my question is the person who got layoff, can she apply for transfer on OPT dependent? And what is the process to get transfer?how long it takes to get transfer?

You can file I-539 but need to submit this form 90 days before your employment contract is terminated, otherwise you would have to apply for dependent visa at the US consulate in your home country.