At one point, Jane tells Adèle to come with her and refers to Adèle as "Madame" rather than the proper form of "Mademoiselle" which is used for a young, unmarried girl.
During the first meeting between Mrs Fairfax, Mr Rochester and Jane Eyre; Mrs Fairfax serves tea and then sits down with her cup. The cup she is holding is clearly empty.
The teacup that Jane is drinking out of is Belleek. Belleek porcelain was first produced in 1863 and was not widely available outside Ireland until the mid-1860s while the blue mark on Jane's cup was first used in 1993.