Here are guidelines for EO dilution rates that are focused on children. The information comes from The Tisserand Institute, a reputable source of information about essential oils.
Please be aware this info-graphic gives general guidelines for EOs that are "GRAS" (generally recognized as safe). There are some EOs are not safe for children (or adults) at any dilution. A quote --
"...there can be exceptions when lower (or higher) dilution is appropriate, or where an oil should be avoided altogether for safety reasons...."
See: http://tisserandinstitute.org/learn-more/recommended-dilutions-for-children/
Please be aware this info-graphic gives general guidelines for EOs that are "GRAS" (generally recognized as safe). There are some EOs are not safe for children (or adults) at any dilution. A quote --
"...there can be exceptions when lower (or higher) dilution is appropriate, or where an oil should be avoided altogether for safety reasons...."
See: http://tisserandinstitute.org/learn-more/recommended-dilutions-for-children/