I don't know if this kind of approach helps or is too abstract, but several months ago, my therapist harvested some flower seeds that she gave me to plant. I had to wait months to put them in the soil and now they are finally starting to sprout, along with a tree that's been budding (she suggested planting it about a year ago, but I planted at the wrong time and had expected to die).

These are all visual and daily reminders of many things, including connection that doesn't go away even if it's not visible. And to your point, they are also evidence of being thought of when not in session because the harvesting and drying took some time and effort on her end.

So maybe there are other things you can come up with to help create the feeling you need while she's gone?