So depending on the definition of "country", the oldest existing democracy is either Finland (1906-) or Norway (1913-)?
Finland: Universal suffrage from 1906, as an autonomous grand duchy of the Russian Empire. Independent country from 1917.
Norway: Independent country. Universal suffrage from 1913.
Or maybe, depending on the definition of "suffrage": New Zealand: Women can vote from 1893, women can run as candidates for some positions from 1919, Women can run for all position from 1941.
You don't give much weight for women to be able to be lawmakers themselves? As long as women have the right to vote male candidates to an all-male parliament, the suffrage is universal enough for you?
Clearly, in this case everybody being given that power of determination from 1893 has worked out well for them on the female representation front looking at current stars on the global leadership stage.
Democratic traditions in other countries long predate even the existence of the US; it wasn't the first with universal suffrage; it had a troubled history even after that till at least the 1960s, even before we get to any contemporary problems.
I don't know there is a legitimate claimant on the "first democracy" title, or even if we are there yet, but unlikely the US.