My friend that is throwing the shower (and we aren't even super close, but she loves party planning) is 6 weeks behind me with her 2nd child. She originally wanted to do a gender reveal party for herself, but because another friend of hers is doing one and they are due around the same time so she changed her mind.
I feel a little guilty having a shower thrown for me, and I'd like to do something for her as well.   Does anyone have any suggestions of something that I can do for her, and I have no problem if it's during my shower as well.  I just want to show my appreciation.  
Re: Friend that's throwing shower is pregnant too--wwyd?
Offer to baby sit her little one while her and DH go to dinner and a movie. You could buy a dinner or movie gift certificate.
Offer to baby sit for her so she can get a manicure or pedicure. Buy her a spa gift certificate.
Invite her to go to lunch and shopping (or something else) with you (if you know she can find a sitter or her DH is home).
I wouldn't do anything during the shower.
When you've been married this long, you need a ticker to remind you.
Baby Boy M - 08/01/2013
Expecting Baby Bean February 2017
I'm throwing my friend a shower and she is 5 weeks behind me. I'm not expecting anything in return (this is my second and I don't want/need another shower). We are very close though is the only difference.
My guess is that your friend is like me and not expecting anything in return (just enjoying being part of you celebrating your child!). I would just get her LO a gift around the time they are born.
My BFF is also pregnant with her first - 8 weeks behind me. I've been thinking about getting her a certificate for a prenatal massage as a thank you.
And I only hope I can throw her one - I think she wants to have hers around the time I'm due. So I'll have to split responsibilities with her cousin or someone in case I have to miss it.
First Son - born 2013
Third Son - due June 9, 2018