Assalamo Alaikom dear Brother,

Yes, in Islam, one can marry his cousin sister’s daughter. Actually, a Muslim(ah) can marry his/her too-I mean by the cousin here the aunt’s or the uncle’s daughter or son.

Allah –Subhanahu wa Ta’ala- said to his Prophet: (O Prophet! Verily, We have made lawful to you your wives,…and the daughter of your AMM (paternal uncles) and the daughters of your AMMAT (paternal aunts) and the daughters of your KHAL (maternal uncles) and the daughters of your KHALAT (maternal aunts)..(33:50).

Allah –Subhanahu wa Ta’ala- also counted for us the prohibited women for marriage in the Qur’an (4: 22-24) and cousin’s daughters were not included in them.

This answer is from a religious point of view. After that you may watch for the local law and/or culture of your locality. Marrying to cousins might not be legal or practiced in some locality. Considering something to be Halal (lawful) does not mean you have to do it.