Perhaps best addressed by posting a sample image.
Can you upload one and provide a link?
If you only have LR, and not Photoshop, then a couple techniques come to mind: using the HSL sliders to limit a hue adjustment to the range of purple in the skin and adjust the hue toward red and maybe desaturation a little as well, and/or loading the adjustment brush with a yellowing tint adjustment and maybe some desaturation and brushing over where the baby is. Both of these have some difficulty in limiting the adjustment the exactly the area you want, seamlessly blending with the rest of the photo and making the adjustment do the right thing.
Seeing a screenshot of the image will help others understand the amount of hue adjustment you want to perform, and actually having an example raw file to play with in LR will help others give precise advice for the particular image. You can upload an example raw to http://www.dropbox.com/ and post a share link to a reply here, and deleting it from dropbox after the advice is given to keep it from being downloaded by others forever into the future.
If you have Photoshop then what you do is put the baby on its own layer using masking or selection and do color adjustments differently on the baby layer than the background layer with the rest of the photo.
While I try to do as much work as possible at the raw processing stage, I'm in agreement with ssprengel when he suggests doing in Photoshop if you have to separate the correction of the baby's skin while leaving the other's alone. It is just the best place to do this kind of selective color correction.