Thank-you Cards

You can open it and then just send a thank you card right away.

You should always send a thank you card ASAP after you receive the gift. This also helps the sender know you got it. I know I always get anxious when I see my package was delivered and I haven't heard from the person. I always assume it got stolen off their porch or something.

Send the thank you when you get the gift. Your future self will thank you!

You should always send a thank you ASAP.

Send it now before you forget. Not that you would but it’s just easier.

I always try to send a thank you note a day or two after getting a gift.

I agree with everyone that in most cases, you should send a thank you note ASAP. However, if there's a virtual component to your shower and you think she'll come to that (or if she's really old/traditional and wouldn't want you to open it early), you can just text/call her to say, "thank you for the gift, I'm really looking forward to opening it at my shower," and then send the real thank you note afterward. That way at least she knows you've received it.

I would send it now. Thank you's should be sent as soon as you receive the gift.