I am a Rebecca and i have 2 SIL's Rebecca (yep there are 3 of us!!) DH Sister is Rebecca Anne, I'm Rebecca Ann and DH's Brothers Wife is Rebecca Jane. (confusing at Christmas!!) lol and we all get called Bec. Also my MIL Is a Ruth and Her MIL is also a Ruth!! lol

But i love the names Rebecca and Ruth, altho i have been banned in using either name for our little girl when she comes along!
I think spelt Rebecca for your little one would tie in perfectly with her brothers and sisters.