In the State of Indiana, when an ex-wife remarries does she lose her portion of the ex-hsuband's pension as with social security

Most likely not. While this is issue is controlled by state law, pensions are normally considered to be marital property, at least to the extent that the pension accrued during th emarriage. When people divorce, the marital portion of the pension is what is divided as part of the equitawble distribution of assets.

Please note that I do not practice in your state and that the above is not intended as legal advice. You should consult a family law attorney in your state who can review the divorce decree and provide specific advice.