Scared of stealing thunder

[Mamamamamamama]

So I've just found out I'm pregnant with my second child. My sister in law has been desperate for a baby for ages and is now pregnant and about a month ahead of my pregnancy. No one knows about this yet as I'm so worried about stealing her thunder .. or her thinking I am .. which I am not as this was not planned!! What should I say should I wait for her to announce it to people or just tell her?

I would respectfully do everything a month later than she does. I would tell her in advance but after her announcement so when she does announce, she will feel centre of attention.

I was in a similar situation to you SIL and was glad my SIL was pg as it kept the pressure off me and of course the cousins are great friends. A cousin will be the best pressie for you niece or nephew as they may not have another sibling. In your SILs position I was happy that my SIL was pg and I'm sure that you are being considerate enough and hopefully she is just glad to be pg and healthy.

I would respectfully do everything a month later than she does.

I agree with this. Let her make an announcement etc in her own time, it sounds like she's had a long road to get to this point.

I agree with doing everything a bit later than her.
Do you get on well with her? Maybe you could tell just her and have it as sort of a shared thing between you? That way she'll know that you're about to announce your pregnancy and won't think you're trying to steal her thunder?

Yeah I don't want to step on her toes at all!! Maybe I should wait longer than that too let the dust settle etc so she's got main attention for a bit! Ahh this is so unexpected to be fair we do have a good relationship but I know what she's like she would make a joke about it but I just hope she isn't upset about it!!!