Help me write to friend dealing with IF

Sagen

My dear sweet friend TTC for years and is unable, and has now been trying to adopt for a few years. I have three kids, and I was pretty sure we were done. I think she found comfort in the fact that I was not going to have a baby, since everyone around her is getting pregnant, but DH and I decided to have another.

She will be one of the best mothers I know when it happens for her. I hate that it hasn't happened for her yet. I hate that I have to tell her, and I feel like I betrayed her in a way.

 I have been trying to write a letter so she doesn't have to put on a happy face for me ( which I know she would). I am stuck, and I keep over thinking everything.

Do I sound excited about it? If I down play it will it be annoying that I am not more grateful? Will it be annoying if I am too happy and I am rubbing it in her face?

Do I mention why I am writing a letter, explaining why I am not telling her face to face?

I can't get this thing right, because everything I write feels like it could be potientally hurtful, perhaps it is because I think no matter what I say it will be a little hurtful.

I have seen the HB twice and will hear it on the 25th, if all goes well I will send it then.