I don't know whether your pay will go up or not, as I am not familiar with the specific rules and it depends on why she was getting payments (alimony, assets distributed by QDRO, etc.)
If she was getting her own separate 1099-R, then you don't need to do anything with respect to her passing. Whatever you get might or might not increase, but whatever is actually paid to you will be reported on your 1099-R.
If you were being 1099'ed for the entire amount and issuing her a nominee 1099-R, you may want professional tax advice. Any amount owed to her that is paid after her death must be paid to her estate, which will have a different tax number.
(You may need to notify them of her death, in case her other family did not, but you may not be able to get a copy of her death certificate. When her death is reported to social security, that should also eventually make it over to DFAS.)