Daughter doesn't want to know us

On new years day they were going back to America. My daughter said dad will drop me off on the way she lives near the airport, i said i dont think we will be able to fit you in. My son had 4 cases and a massive holdhall. Also my daughter had her travel bag and 3 bags of christmas presents. I said when we drop our son off we will come back for you. She then got the phone and phoned for train times. I then said we will try to fit you in and bring the presents up later.

She took no notice and just left. She shouted to my son goodbye but never said anything to his wife. She has never rang us since. We got through after ringing numerous times and asked if she had fallen out with us. She said no, we said we can bring up the presents she made excuses, saying she was going out. We have emailed her and one day we spoke to her friend, we rang our daughter again. She answered and said stop harrassing my friends. We have not been in touch since. No mothers day card or 60 birthday card for my husband.

What makes it more upsetting we have both had ill health, my hasband had prostrate cancer had his op jan of last year. I was diagnosed with breast cancer had my op 3 weeks before christmas. She knew i was starting chemo in january and has never asked how i am. What can we do now.