There is no separate index to Rev. War Pension applications by widows.
has an every-name index to Rev. War pensions. They have a free-trial period. So try there.
Be aware that most widows were not eligible to apply until at least the 1830s, even if a husband were killed during (say) local militia activity while he was on active duty.
Check the State Archives' published listing of bounty land warrants issued - but I am not sure whether militiamen's widows were eligible.
A lot of people died during the war of causes unrelated to being on active duty, such as of smallpox.