"My daughters sleep."
Translation:Filiae meae dormiunt.
In short: no. More details:
Most of the nouns of the first declension (ending with -a in the nominative singular form and having the ending -ae in pl N) are feminine - patria, mora, femina, silva etc, but there are some exceptions: poeta, agricola, pirata, nauta etc are masculine.
-ii is not the ending, only the last -i is. Fili- is the stem of the noun fili-us. This is a noun of the second declension which includes the masculine nouns ending in -us, -er, -r and neuter nouns that end in -um, as well as the borrowed Greek masculine (-os) and neuter (-on) nouns. The masculine nouns of the 2nd declension have the ending -i in plural nominative.
In total, there are five declensions of nouns in Latin.
That is correct. The third declension nominative (subject) ending in the singular is "given" meaning that unlike the first or second declension, there is no pattern to recognize it by. Some third declensions, like pater and frater end in er, some like canis and panis end in is, some like nox and nix (night and snow) end in x, etc. etc.
Usually. Basically, in Latin, there are 5 declensions of nouns. Filiae is a 1st declension noun, most of which are feminine. First declension nouns follow a pattern of endings for different cases. Look at http://dcc.dickinson.edu/grammar/latin/case-endings-five-declensions for more information.