Friendships lost

A year and a half ago we moved right across country. We had lived in our previous town for 3 years. Now we don’t travel back as it is a long journey and we have young kids. I miss one of my friends a lot. Initially when we moved I tried to keep in touch and suggested meeting up midway between us a couple of times but this never materialised. I tried to remember her kids birthdays (her son and mine were best friends until we moved) but ended up forgetting. We exchange text messages about twice per year usually when something bad happens to check in (such as coronva virus and the explosion in Lebanon as that is where her family live). I feel that I have lost the special friendship that we had which makes me sad. I also have a thought that she is too busy for me as even when we did live close by it was hard to get together due to her family schedule but when we did we really had a great time together. Wondering how to move through this feeling of sadness and loss of friendship? Thank you