We are given a reason for Aaron and Moshe not entering the Land of Israel. But we are never given one for why Miriam died in the desert and was not allowed to enter Eretz Israel. Is there any reason given in the Talmud why she was not allowed to enter as she did not participate in the episode of "Mei Meriba"? Thank you in advance.

I found no good answer to your question. There is however some indication to the fact that she did not sin and yet was not permitted to enter The Holy Land for reasons only Hashem knows. [Ramban Devarim 32; 8] The Meshech Chochma [Bamidbar 20; 28] adds that since the place she was buried will in the future be part of Eretz Yisrael, she [and Moshe and Aharon for that matter] was buried within the borders for of the promised land.