"Two women are hugging grandma."
Translation:Kaksi naista halaa mummoa.
"Kaksi naista" is indeed grammatically singular (numerals other than one demand the noun to be in singular partitive), so the verb is in singular as well. (The plural of "nainen" is "naiset", "naista" is partitive singular). If there were no numeral "kaksi", it'd be "nainen halaa".
In "nämä kaksi naista" the "nämä" (these) is plural. "Nainen" is again only in sing. part. because of the numeral. If there were no numeral, it'd be "nämä naiset halaavat". I guess the "nämä" makes it more of a plural, and so the verb acts accordingly.