Advice please - Here's the short version:

Haven't seen her in 6 months.
Haven't spoken with her in 5 months.
Haven't communicated via text in 2 months.
Sent a card 6 weeks ago (no response).
No acknowledgement of my birthday 3 weeks ago.

Question - Should I send another card to "test the waters"? If so, when? Or should I assume she's not interested and leave her alone. Thanks!