Traffic/airport advice

Google maps is saying that time of day to allow 45 min for the 17 miles trip about that time of day (leaving at 9AM or 10AM, time's the same). It's a mix, you'll be on the way out when commuters will be on the way in, but Heathrow itself is like a small city, so planning on being on the early side looks prudent. Seems like the M4 highway is involved, so watching for any traffic trouble on that road that morning might be good. Might be best to tell your landlord a slightly earlier flight time, just to be on the safe side.
Imperial Wharf looks like a good area, near Victoria Station which has coach buses that go everywhere, near Kensington, looks like it'll be great location but maybe slightly lower cost. Have fun!
-Alison

I would allow an hour in case there are traffic issues in central London. You will be after the rush hour, but London is always busy.

As a translation for those that have never experienced the Westway or the M4 motorway: did you ever play driving games like Out Run or Ridge Racer? It isn’t like those, but it can get a bit exhilarating.

https://youtu.be/EZu-KnKrG8E

As an alternative it really isn't that difficult to travel to Imperial Wharf by public transport although there are some unavoidable stairs: Piccadilly Line to Earls Court, District to West Brompton, Overground / Southern to Imperial Wharf. Typically 50 mins or so at the somewhat bargain price of £1.50 off-peak as you don't go into Zone 1.

BTW Imperial Wharf is in Sands End, and is named after the old gasworks that used to be there - indeed one of the former gasholders is the oldest in the world and is preserved as a listed building.

Thanks everyone! I figured the traffic would be like Atlanta's can be at times. We will probably do the taxi though as my mom will be with us and I need to make it as easy as possible.

Thanks everyone! I figured the traffic would be like Atlanta's can be
at times. We will probably do the taxi though as my mom will be with
us and I need to make it as easy as possible.

To make it easy, it is understandable that you don't want to take public transport that involves changing trains. A local London taxi will be super expensive, however, especially from Imperial Wharf; remember they run on a meter so you will be bilked to the gills with that running meter.

Consider Simply Airports. You can get a direct quote online that will be HONORED. No meter. Excellent/polite drivers and comfortable vehicles.

The owner will most likely be arranging a minicab rather than a taxi.

Although I already suspected the OP had a specific reason not to use PT I thought it worthwhile mentioning the route anyway in case it helps someone in future. It can be entirely stair free in one direction; the problem is with the West bound platform at West Brompton.

Thank you Continental and Marco. I would rather do public transportation but unless my mom thinks she can manage it, her knee still gives her problems at times, we'll have to stick to a car ride. I'll definitely look at the website you suggested.

How about a taxi to Paddington and then Heathrow Express to the airport...the taxi will take about 20+ minutes and the express train is 15 minutes. Very easy!