Malama was in her hospital until december 1914, then he came back to war. Tatiana saw him another time in 1916 (see Alexandra's letter).
Kiknadze was in 1915 and 1916 (for exact datation, see the diary entries in that thread).
Was she in love... Well, I was not Tatiana's confident...! In a letter of the end of 1914, Olga Alexandrovna (their aunt) joke about Tatiana's tender feeling for Malama. Alexandra herself told he would have been a good son for her if...
About Volodia Kiknadze, I do not know exactly. Diary entries and Chebotareva's account show she evidently was very fond of him, they spent a lot of time together and it was an occasion of gossip in the lazaret. Volodia and Mitia were specially distinguished when Anna Vyrubova invited them for a party.
Perhaps Helen A or Reagan, who read the GD's diary entirely, if I am not wrong, could tell us more (if they have the right, I do not know).