There is probably no way around genetic testing, and it should be done as soon as possible. It may not even ich at all, let us hope.
Confirmation that it is not vulgaris is both good and bad. It is good that it is not the most prevalent form of ich, and therefore it may not be ich at all. It is bad because if it is ich it would be one of the rarer but more severe kinds.
Biggest concern is the impairment of cooling function of the skin, sweating. With vulgaris and even severe vulgaris, there is still an underlying ability to sweat. However, with lamellar or CIE, even minimal sweating becomes very difficult. If the child is unable to sweat, keeping the child cool and comfortable becomes the highest concern.
For the sake of caring for your daughter as much as the decision to have more children, you should get genetic testing done as soon as possible. And if it is a particular type of ich, then contact F.I.R.S.T