I assume you mean how to handle any potential inheritance you might have from the estate.
First, get all documents from officials in the Dominican Republic through official channels, not from someone you are emailing.
You need to be sure your dad was legally married at the time of his death, and to whom he was legally married. Second, you need to see that death certificate rather than relying on word of mouth from someone with an email account. Probably she inherited 100% of assets as a spouse, but you need someone to check into whether he had a will.
Bear in mind that you may be in line to inherit assets if the bereaved wife dies. If dad was a multi-millionaire, this could be a lot.
To accomplish all this, I suggest hiring a lawyer in the D.R. Hire a lawyer in your home country to help you find the lawyer in the D.R. and translate if necessary.