Why is it ironic, or contrary to what you might have expected , that freeman considers the deed of manumission to be so precious

(from a soldier for the crown)

it might be ironic that freeman considers the deed of manumission to be precious because she is happy that she owns a pass for the British so that she can be freee but if she shows her true identity then she is scarred that they are going to take it away from so she is unsure if she is free or not. On the pass it says her name is "alexander freeman" and it’s not her because she is a girl and that is her name to get by so she cann be free. she claims an identity that isnt hers to be free. the deed of of manumission is precious because its what emancipated slaves and freed them. 

-hope this helps