Thank you very much.
For those who do not know, the TMDb rule is to keep the oldest, the smallest ID.
OLD 0 https://www.themoviedb.org/person/1935775-rachel-montgomery
new 1 https://www.themoviedb.org/person/2169937-rachael-montgomery
IMDB https://www.imdb.com/name/nm2699067/ Rachel Montgomery (I) - Miscellaneous Crew | Second Unit Director or Assistant Director | Producer
IMDB https://www.imdb.com/name/nm6022518/ Rachael Montgomery (I) - Actress | Director | Writer
WIKI

In Rachael Montgomery (I) Demo Reel the name on the credits is Rachael Montgomery.

Maybe they're two different people.
Are you sure it's the same person?
What is the correct name? Rachael or Rachel?
Can you indicate a good source?

TIP: If you want to force the line break, click Space 2 times and then click Enter. Just Space > Space > Enter.

Hi @ticao2 , I can show you a frame for the episode she was credited: http://images2.imagebam.com/ca/f9/40/e62dac1026190334.jpg and here it's definitely visible that we are talking about the same person: http://www.imagebam.com/image/3431b21026191594 Thanks in advance.

They are 2 different persons (unfortunately, IMDb's entries are slightly messed up, and it seems the official episode credit is wrong and the reason for IMDb's mistake):

1.) The actress is Rachael Montgomery, her official website, facebook and instagram are here:

https://www.rachaelmontgomery.com
https://www.instagram.com/rachaelmontgo
https://www.facebook.com/rachael.montgo

On her website, you can find a résumé that lists many stage and a few film/television roles, including the episode of "How We Got Here". But there's no indication that she worked on so many productions as an assistant director -> she seems younger and doesn't have the education for working in this capacity. Also, according to her facebook page she's from Wichita Falls, Texas - not Lynn, Massachusetts.

2.) The assistant director is Rachel Montgomery, you can find a list of her work here:

https://www.mandy.com/crew/profile/rachel-montgomery

She's currently associated with a production company called "Hectic Films" -> that's her profile:

http://www.hecticfilms.com/about/the-crew/rachel-montgomery-producer-director-ad/

The movie Naked Zombie Girl was done by "Hectic Films". The other one, The Mandela Effect, is in post production and I can't find much about it. But most likely it's this Rachel Montgomery who's involved in this production.

EDIT: According to her facebook page, she's married to Rickey Bird, the director of Naked Zombie Girl. And she's not from Lynn Massachusetts, but from East Hampstead, New Hampshire, 30 miles north.

I fixed both TMDb entries.