Adoptive parents becoming distant

My adoptive parents have become distant.. Our adoptive parents, through our agency contract have to send updated pictures once a year, usually they send at least 6 pictures all with captions on how she is doing and how much she's grown. This year was only 2 pictures, no captions. I feel like as she gets older they no longer want to share her with us. When we first met our agreement they said it would be fine to send birthday cards. they even gave us their home address to send them to. (Our written contract says to send to the adoption agency to pass on). I never have because I felt I should give them their space. I'm hoping they haven't taken that as a lack in interest. I think about her every day. I'm wondering if I should send a card (she'll be four this year) or have I gone to long without sending anything that at this point it's over stepping my bounds.. Am I too much in my head about this? Any advice is appreciated