Princess Kate Forced to Cancel Another Official Engagement
10/08/2014 AT 08:20 AM EDT
Kate, 32, was set to visit Sir Ben Ainslie's America's Cup team base in Portsmouth, on England's south coast, next week, PEOPLE has confirmed.
The palace had not announced her appearance, and officials there are keeping a close eye on what she can and cannot do in the coming weeks.
A spokeswoman would not comment on the cancelation but repeats that they are taking things on a "day-by-day basis" as Kate and her doctors work out when and if she is up to appearing in public.
Spending time at her parents' home in Bucklebury, 50 miles west of London, as well as resting at Kensington Palace, Kate has not been seen since the palace announced she was pregnant on Sept. 8.
Since then, she has had to pull out of a few engagements and was replaced on an official visit to Malta by husband William, also 32, who told well-wishers there that she was feeling "so-so."
The Daily Express, which broke the news of this latest cancelation, said the event was to have taken place on Monday of next week.
Kate, an avid sailor, had helped launch Olympian Ainslie's American Cup bid in June. She also chatted about son Prince George starting yachting lessons one day.