因缺席生日晚餐向朋友道歉Unable to attend friend birthday dinner

Dear Leo, I'm really sorry, but I won't be able to come to your birthday dinner on Saturday after all. My sister has injured her ankle, and the person who was going to stay with her that evening is no longer available. I've offered to help her at home and look after the children until Sunday morning. I know you've already booked a table for everyone, and I feel awful about changing my plans so close to the day. Please let me know if the restaurant needs you to confirm the number of guests again. I was really looking forward to seeing you and hearing about your new job, so I'm disappointed to miss it. Could I take you out for lunch the following weekend instead? There's a new café near the river that I think you'd like. I'm free on either Saturday or Sunday, so choose whichever works best for you. We could go for a walk afterwards if the weather is good and have a proper catch-up. Have a brilliant evening, and please send my love to everyone. I'll call you during the week to hear how it went. Sorry again for letting you down. All the best, Alex