I'm not sure that the future perfect would convey what the OP intends. I do think something like serva me; te servaris "save me and you'll have saved yourself" would make an interesting sentiment, but the OP seems to be suggesting she means something more along the lines of "save me first, then I'll save you". Serva me; te servaro would mean something more like "Save me, and in doing so you'll be saved by me". She'll have to further clarify on what precisely she means, though.
I still think just serva me; te servabo would work. There are two examples from Plautus' Rudens which, though of an altogether different character than this request, nevertheless validate the construction:
Verbum etiam adde unum; iam in cerebro colaphos abstrudam tuo.
"I dare you; utter but a single word more and I'll bash your brains in straightaway."
Tange; adfligam ad terram te itidem ut piscem soleo polypum.
"Come on, touch me; I'll slam you on the ground like I do the cuttle-fish."
Thus I disagree with Nikolaos that et is required, or that me and te could be confused in serva me te servabo: it would be unnatural to interpret the two separate clauses as mixed. However, to draw a more explicit conditional connection between them you might add a word like tum or ita to the apodosis: serva me; [tum/ita] te servabo. I don't think it's strictly necessary, though.