Need help with Legends of Dragoon question for PSX (spoilers

[pr-man 1]

ok I am at the point where King Albert has been kidnapped and Shana now has control of the Silver Dragon Spirit. I have been using Lavitz, Dart and Rose for the whole game so they are all at level 12. Shana is only level 9. I have a feeling that I will really need Shana's dragon Healing powers down the line in this game so should I concentrate on upping her levels before I go to rescue the king? Also what is the best way to raise her EXP since with a party of three she barely gets any after each fight. Thx