Greetings to the Fodor’s United Kingdom brain trust! Next April my friend and I will be traveling to London, Kent and Amsterdam. We are in our mid 70s and have been friends for 60:years. We don’t want to drive and prefer to stay in one hotel per region. All of this is new for my friend. I’ve been to London many times, but the rest is new for me as well

We fly in mid April from SFO to LHR. Have reservation for 5 nights at Rubens on the Palace (will continue to look at other options).

Our next stop,is Kent and this is where we could really use some insights and assistance. My friend’s daughter-in-law has done significant genealogical research and identified places in Kent where her family is from. We have narrowed down where we want to visit to Canterbury, Sittingbourne, Westgate, Herne Bay and Margate. We have allocated 3 nights.

After looking at the map and train schedules this is our tentative plan:

4/16 take morning train from St Pancras to Canterbury. Check in to Canterbury Cathedral Lodge. Explore Canterbury including the Cathedral..

4/17 take train to Sittingbourne to explore town, particularly St Michaels Church where her grandparents were married. Take train back to Canterbury for the night.

4/18. Book either a taxi or car and driver for the day to take us to Westgate, Herne Bay and Margate. These are fairly close together and we have a few particular places to visit, but also just want to see these areas that were part of the daily life of her ancestors. Return to Canterbury for the night.

We would appreciate any referrals for taxi or private car and driver. Or, other suggestions for how to,get around short of renting a car and driving ourselves.

4/19 take train from Canterbury to St Pancras and catch Eurostar to Amsterdam.

Does this plan make sense, or is there. Better way to lay it out? Appreciate insights and suggestions!

Sittingbourne won't take all day.
Have a look at bus routes, there are plenty from Canterbury that go to the places you want to visit.
Currently costs 2GBP a ride on the buses. I don't know how long that will last though.

https://www.stagecoachbus.com/plan-a-journey

Great idea to take the bus. We’d still need a way to get to some locations within the towns. Do you know if Uber is reliable? Or, we could take a taxi Assuming we can find one).

The towns you mention are not big and generally pretty walkable.
My MIL used to live in Canterbury and using her free bus pass would visit all the towns you mention, almost daily., right upi until her final illness when she was 96.
My SIL lives near Faversham so we have been to them all many times as well, but by car.
Be prepared for changeable weather in April - rain, sun, wind, cold, warm, all possible, often all on the same day.

No -- you definitely wouldn't need uber to visit places in any of those places:

Assuming you mean Westgate-on-Sea -- Margate/Herne Bay/Westgate-on-Sea are all connected by very short train rides. Once in each town most things are walkable or short bus rides.

. . . One of my best friends grew up in Margate and never owned a car until she moved to the States. Was absolutely no need (and uber didn't exist)

Thank you both for the helpful information.

Reworking our itinerary based on your input. We want to go to Dover so am thinking we can do that on 4/16 leaving from Victoria Station to. Canterbuty East dropping luggage at hotel then on to Dover. Then Canterbury and Sittingbourne on 4/17.

Please let me know if you have suggestions for interesting/pretty places to visit in these towns since we’re partially there just get a feel for the towns. Would also appreciate any recommendations for restaurants or cafes. Looking for local, good food, seafood. Not fancy.

Just very quick re Dover -- The castle is magnificent and can take most of a day - several hours at least. It is less than a mile from the station - but don't even try to walk it since it is up a steep hill. Take a taxi from the station up to the top. Not much else to see/do IN Dover and parts are pretty seedy. But also nearby and easy/very short short train rides from Dover are Walmer Castle (once a fortified castle now a beautiful stately home with gorgeous gardens - the Queen Mother often stayed there) and Deal with a fascinating castle and seaside cafes etc.

oh -- re Dover castle -- it isn't just the actual castle -- but also all the WWII facilities including the hospital, a Roman lighthouse, views forever etc.