Hi Erin!
In order for products containing essential oils to be safe for babies they must have only 0.05% essential oil content, and they must be essential oils that are safe for babies (ie: lavender, roman chamomile, mandarin). Our Sweet Baby Oil and Restful Room Mist are both products made specifically to help soothe fussy babies, and both contain essential oils safe for babies in a 0.05% concentration. Tinctures tend to be quite strong, and I wouldn't recommend using them for either an infant, OR a nursing mom without talking to a naturopathic doctor first. Calendula infused base oils should be fine to use on the baby for healing skin irritations, but if you delay bathing your baby – allowing the vernex to remain protecting their skin for a day or even a week – their skin is less likely to become irritated at all, thus preventing the need for skin cream! I also suggest that when you DO bathe your baby, use only water, or a soap that contains no SLS, scent, colour etc. – this I think you know though :) This will also prevent skin issues. Lots of naked time is another good way to keep baby's skin healthy! As for oils in the bath or to massage baby afterwards – avoid nut base oils, and of course no mineral oil, and as I mentioned before – ensure the concentration of essential oil is no more than 0.5%.
Another "must have" in a medical kit is homeopathics! Homeopathic remedies are far safer than herbal remedies, and are great for pregnant moms, labouring moms, babies and nursing moms. I've found them to be highly effective for gassy, teething, and fussy babies and children. Most natural health food stores have basic remedies, and consulting with a homeopathic doctor for acute conditions is always good to do (many will do phone consults if you cannot make it over).
Best of luck, and I'd love to hear what you complete your kit with!