As a recap, I am due in August and have a 3 almost 4 year old SD. DH is not from the US and my ILs live in the country in Europe he is from. His dad speaks a little English, his mom none.
I don't want to create things to worry about, but lately I've been concerned about SD feeling left out of the relationship between my ILs and my DC. SD only speaks English and is unable to really communicate with her grandparents. DH does call them on Skype 2 to 4 times per month when she's with us, but there seems to be a lack of connection there. DH has not yet been able to take SD "home" though we're hoping to be able to next year without getting courts involved.
DH will be a SAHD with this baby and will be able to teach the baby his language. His parent's have already made plans to come to the US twice in the first 6 months of our baby's life and are flying DH's adult brother out with his girlfriend one of those times. whereas they have only visited once in SD's life, and she's never met her uncle. They just seem more excited, I think in part because they feel like they'll be able to have a closer relationship with this child. But, I don't want SD to feel left out. Obviously she'll see them when they visit, but the stated reason for both visits is to see the new baby.
Has anyone had a situation similar to this? Do you think SD won't really notice/care since she barely knows who they are anyway? Are there things DH should be doing?

Re: IL relationship with SD versus DC
I realize you don't have SD all the time, but the more your H is able to teach her now the better. Kids are sponges.
So where is your DH in all of this? What has he done to foster a better relationship between his first child and parents/family?
It is all well and good that you care, but if your DH doesn't seem to want to put forth the effort, why would your InLaws?
DH not having taught SD any of his language is one of his regrets. He didn't teach her when she was younger and he spent more time with her. Now, she doesn't understand when he speaks to her in his language and they both get frustrated. The language he speaks is not an easy one to support where we live because not many people speak it. In order to teach the new baby, we have put together a whole language plan that includes traveling a bit to join small play groups where they so speak it. We aren't able to do that with SD because of the parenting schedule.
As far as the Skype calls, again, I think DH and SD get frustrated and so they don't always last long or go well. I think that DH could probably try harder to facilitate them.
Thanks for the advice! I will work with DH to make sure we're all on the same page about the expectations of the visits. Ultimately I know it's something he'll have to work out with his parents, I just know I won't be comfortable if things are blatantly different between how the kids are treated.