Both were recovering well on Thursday afternoon, according to her Facebook post.
A spokesman for Auckland Council said its pollution response team had been notified.
"While prior to this we have not been made aware of any issues at this particular location, as a general rule we advise against swimming in coastal streams as they have a tendency to suffer from pollution issues and are not considered safe for swimming in."
No possum control programmes were currently taking place near Kakamatua Inlet, he said.
Auckland residents concerned about any water quality should make a report to the Council's pollution hotline on 09 377 3107.
More information can be found here: https://www.aucklandcouncil.govt.nz/environment/looking-after-our-waterways/Pages/report-water-quality-issue.aspx