A little preparation goes a long way.
Give each major visit its own day, with arrival and departure buffers.
Start with arrival and departure
An outline is arrival, Palace Museum, Mutianyu, either Summer Palace or Temple of Heaven, then departure. It leaves three full visiting days. Flight times can reduce that, so the arrival day should not be assumed to be a full sightseeing day.
Palace day: confirm the visit first
Advance booking is needed; the museum normally closes on Mondays, with exceptions to check. Build the plan around confirmed availability. A more selective route can help, but does not remove walking or queues.
Great Wall day: access and wall walking are separate
Check the operating service, tickets and meeting points for uphill transport. Steps and slopes can remain on the wall. Keep the wall section modest and avoid adding a compulsory long evening walk on return.
Choose on day four rather than adding everything
Choose a main visit rather than insisting on both landmarks in one day. A shorter park or neighbourhood visit can be discussed if needed, subject to tickets and service changes. The outline is not a guarantee of physical suitability.
Start with these details
Message “Beijing with parents” with month, group and two priorities.