Remembering how the EUput pressure on Lithuania during the conflict with
China, I have a damn doubt they support their ally in the conflict with Russia. In the place of Lithuania, I wont count on anything from the EU other than requests/threats to cede to Russia.
Lithuania is in NATO, so it's unlikely to cede anything tangible. If the Baltic states hadn't joined NATO I'm sure Putin would have invaded them first and not Georgia or Ukraine.
Economically there is also not much to lose. Trade with Russia is under massive sanctions for decades to come.