Yikes.. She sounds like a young mom with a very busy life.
You sound like a wonderful mom. You remind me of my mom.. Many times, she would call or email and I just really did not have time to answer, when I did it was very late at night or extermely early in the morning. I worked retail so I could not take calls during the day. When I was a store manager it was worse, because I was there 12 to 14 hours a day. I barely had time to see my husband and daughter..
I made a deal with my mom. I told her loved her and missed her. That I was thinking about her, but to please try not to put any pressure on me, because I already had enough just trying to get through the week.
She told me not to worry about her, just to once a week send her an email saying we were alive and well. She also said if we EVER needed anything or any help, she was there. That we should not feel any guilt about only calling when we need something. Boy did that give me peace of mind and heart. My husband and I did start calling on her a little more for help. Sometimes, she would call my husband and offer to pick up our daughter and meet him at the house so he could feed her and get her ready for bed, while my mom prepared dinner. Sometimes, she would be there when I got home, but most of the time not..
My mother also ALWAYS had an open door policy. If we ever wanted to see her, she pretty much dropped what she was doing so we could go and see her. I hated that a few times, she canceled going out with friends, but she said she would rather see us than them.. Mind you, this only lasted for about 2 years, then once our daughter started kindergarten, our schedules were a little more settled and out daughter did not need all of that physical care..
Send her a funny card. Let her know you love her and do not want to add any pressure to her or take time away from her family but that you miss her and any time she wants to call or see you, you will be there.
Let her know some of the struggles you had as a young mom with a young family.. Offer the services you are willing to provide.. Meet the service people at their home. Pick up daughter from day care. Watch daughter every Friday or Saturday night so they can have date night, but promise her you do not want her to feel like she has to respond all of the time, just a few updates, every once in a while on her time to let you know they are still alive and healthy. ..
I am sending you strength. You sounnd wonderful.