Yes, if ingested, the detergent can be toxic to cats. Did you give her a 'full' bath, to remove all of the detergent? If not, do that now, in warm water, and don't let her get a chill. Did she lick herself at all, before you could bathe her? If so, she ingested the detergent and this will cause a health problem for her.
How old is your kitten? Has she vomited at all? Did the detergent contain bleach?
After you bathe her, give her some watered down milk to drink, and watch her breathing. If she's struggling for breath, bring her to the nearest ER vet center, now. If she's coughing and slightly wheezing every now and then, monitor her to see if it improves, and if not, she'll have to be seen by the ER vet. Call the ANIMAL POISON CONTROL CENTER
888-4ANI-HELP(NNN) NNN-NNNN, if you need more information, as they have a list of every product and what it contains, and can tell you for sure, what symptoms to expect. There is a charge for the call.
I hope she'll be fine!