CREATE DATA (Age at first marriage) PLEASE GIVE IN 5 HOURS

http://databank.worldbank.org/data/reports.aspx?source=gender-statistics

You'll probably need to experiment with downloading files from the site a few times before you get what you want. This database also supposedly has Age at First Marriage, but the series is very incomplete, so I would use the aforementioned source instead. From the World Bank I would select variables such as the following:

-female labor force participation
-real per capita gdp (PPP)
-some measure of female education, such as the literacy rate
-infant mortality rate
-% of males who own homes (this one might seem odd, but it can serve as a measure of male marriageability)

Since you're doing a cross section, you just need data from a single year, preferably a year since 2010 that has a high response rate; maybe 2014 or 2015.