2 waysa really, the long way is to modify a file in the missions folder.
C:\Program Files\Microsoft Games\Freelancer\DATA\MISSIONS\M01A
[Trigger
nickname = mrp_accept
system = Li01
Cnd_MsnResponse = accept
Act_SetShipAndLoadout = ge_fighter, msn_playerloadout
Act_SetOffer = 21805
Act_SetTitle = 21800
Act_DeactTrig = mrp_reject
Act_RemoveRTC = missions\m01a\M001a_s005a_Li01_01_offer.ini
Act_RemoveRTC = missions\m01a\M001a_s005d_Li01_01_reoffer.ini
Act_RemoveAmbient = scripts\story\Li_01_Equipment_ambi_s005_ship_01.thn
Act_RemoveAmbient = Scripts\Bases\Li_01_Cityscape_gamestart_01.thn
Act_RemoveAmbient = scripts\Bases\Li_01_Equipment_ambi_s005_music.thn
Act_ActTrig = spe_initialize_end
Act_GCSClamp = true
Act_NagOff = greet
Act_ActTrig = bsx_newnnobj
Act_NNIds = 30020, HISTORY
Act_ActTrig = lce_setfirstobj
The easyest way to get teh ship, is start the game, she gives you the small ship, but before you launch, create a save game other than auto save, then exit the game. Download
Ioncross Char editer and open the saved game file and change to any ship you want.