I think most with this mutation are expected to be salt-wasters (see below).
Also: The notations on either side of the slash (/) indicate the status of each of your two 21-hydroxylase genes. E.g You are "I2 splice/Normal." This means one of your 21-hydroxylase genes (say, the one you got from your mother) contains the "I2 splice mutation." The other (say, the one you got from your father) is "Normal."
The same goes for your husband.
Your daughter, is "I2 splice/I2 splice." This mean she ended up getting your I2 splice mutation. She also ended up getting your husband’s I2 splice mutation.
(BTW, it is probably more common for husbands and wives to carry different mutations. You and your husband just both happen to have the exact same one!)
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http://edrv.endojournals.org/cgi/content/full/21/3/245 (You have to scroll way down to the part where it talks about all the different gene defects.)
3. A or C
G mutation in intron 2. The nucleotide 13 bp before the end of intron 2 (nt 656) is A or C in normal individuals. Mutation to G constitutes the single most frequent allele causing classic 21-hydroxylase deficiency.....
Although it is not known what proportion of mRNA is normally spliced in the adrenal glands of patients with this mutation, most (but not all) patients who are homozygous or hemizygous for this mutation have the salt wasting form of the disorder, indicating that they have insufficient enzymatic activity to permit adequate aldosterone synthesis. Occasionally, presentation of salt wasting signs is delayed until several months of age in patients carrying this mutation (465)......