Op, it's likely this lady's condition would count as a disability under the Equality Act 2010 if her condition if not medicated meets this criteria:
In the Act, a person has a disability if:
? they have a physical or mental impairment
? the impairment has a substantial and long-term adverse effect on their ability to perform normal day-to-day activities
If you were to not employ her because of this condition it would be direct discrimination and she could make a claim to an employment tribunal. This means if you do reject her you have to be very clear as to your reasons and they cannot relate to her disability. If you have already offered her the job and then withdraw the offer because of this you would be on very shaky ground. It might be better to choose an entirely different childcare option such as a childminder and cite reasons such as cost, shared care with other children giving greater socialisation rather than hire a different nanny and run the greater risk of a discrimination claim.
There are exceptions to the Act so if any of the following applies you may be able to reject a candidate without risking a tribunal claim but really, it another family is employing her none of the following are hugely likely to apply and you should get some specialist advice before proceeding whether you decide to reject her or employ her and you need to make any reasonable adjustments.
Section A 12 provides: ?Certain conditions are not to be regarded as impairments for the purposes of the Act. These are:
? addiction to, or dependency on, alcohol, nicotine, or any other substance (other than in consequence of the substance being medically prescribed);
? the condition known as seasonal allergic rhinitis (e.g. hayfever), except where it aggravates the effect of another condition;
? tendency to set fires;
? tendency to steal;
? tendency to physical or sexual abuse of other persons;
? exhibitionism;
? voyeurism.
The exclusions apply where the tendency to set fires, tendency to steal, tendency to physical or sexual abuse of other persons, exhibitionism, or voyeurism constitute an impairment in themselves. The exclusions also apply where these tendencies arise as a consequence of, or a manifestation of, an impairment that constitutes a disability for the purposes of the Act?.