Bobbi Kristina Funeral -- Invitation Infuriates Brown Family Member

Bobbi Kristina will be laid to rest Saturday and her funeral already has the Browns and the Houstons fighting ... over money.

TMZ's obtained the invite ... the guest list is tight and even if you're on the list you have to present a government-issued ID at the door.

Now the conflict -- the invitation suggests, in lieu of flowers, donations should be sent to The Marion P. Foundation, a charity run by Bobbi Kristina's aunt Pat Houston, benefiting troubled teens.

Leolah Brown, BK's other aunt, claims Pat's just lining her personal bank account and she's asking people not to send “ONE RED CENT!” to the charity. Leolah says Pat's "not the sweet quiet person that she's tried so hard to make people believe she was... ." And what's more -- she alleges the late Whitney Houston would agree.