She explains that one has to go through a process to be picked, with several stages of approval.
At first, the show had five housewives, with Dr Masitsa joining later on as the sixth housewife. She explains that one reason is that she was out of the country, in her other home in Europe, so she was away when the show began. But there is also another reason.
"There is always a mid-season shaker, so that's what it was," she says.
And what has her experience on the show been like so far?
"Amazing!" she says. "It is like being in one big party. It is amazing to see the dynamic of the women in terms of having to get along, even though the thing is I knew most of those women outside the show. We kind of know each other because Nairobi is a very open place, so there is some authenticity in that."
Speaking of authenticity, the show is known for high drama, to the extent that one of the most common questions even on Google, is whether the show is scripted, which Dr Masitsa vehemently denies.
"Anybody who knows me, anybody who has followed my career trajectory knows I cannot exist in a scripted world. I run my race. You cannot script me. Why would I play somebody else's lines and sentences? No, I am here to live my life. It is a community so you have got to be a team player, but we are just living our lives. It is not scripted," she says.
She has joined the show as the no-nonsense Queen Mother, and she is passionate about shedding light on what she refers to as the prime-time woman, the woman aged 45 to 70 and represents that target market.
"Why do I feel passionate about that? Because I see 30-year-olds running around really scared of reaching age 45. At the same time, I am also seeing some of the women turning 45 and getting this midlife crisis, feeling like it is all bad. We go through all these changes and some of them need counselling," she says.
She wants those women to understand that this is the high point of their lives, that it is their time now.
"Both of these groups need to be brought together and understand that life is just beginning," she says. "At this age, I feel more joyful. I am embracing life in a very eager way. I feel content and more liberated, living life in my lane and I do not need to fit into anyone's stereotype. I feel more purposeful and confident - I have been there. I have done that. I trust my life skills."
Dr Masitsa is also hoping the business community will wake up to the potential that is in the prime-time woman.
"We do not need a business community that is like, 'Oh you cannot target 45-year-olds because they are set in their ways.' In Kenya today, we are the healthiest, we are the wealthiest, we are the most educated, and we are active. We are influential," she says.
A lot of women in the 45-to-70-year-old age bracket are now empty-nesters, meaning that their children have left home.
"I want to challenge anyone who is business-minded to start looking at these people. They feel that its 'me-time.' And they feel like, 'if not now, when?' So I am ready to spend money on myself. Do you know what that means? We have disposable income. The children have gone through school and left home. So there are a lot of opportunities there. We are ready to adjust our lives," she says.
This, she explains, is in all aspects of life - from real estate to beauty and household matters.
"We are going to dress up in sexy lingerie. Just keep watching the show!" she says. "We are ready to use feminine beauty products, we are ready to embrace housekeeping, grocery delivery - we are ready to embrace all these things. Look at how many business opportunities I have just mentioned."
She adds that rather than looking at that age group as people who are stuck up and with set minds, genuinely talk to them because they can also see through you when you are trying to play games with them.
"Do not try, for example, to sell an expensive car to me using a 21-year-old. No, I can afford that car. Just talk to me. I will appreciate it. For example, I appreciated it when Land Rover used Caroline Mutoko to launch a car. That is my mission in 2025. I am buying that one. She is my contemporary. So what do you mean when you use a 21-year-old? When you use my agemate, that makes sense," she says.
A lot of women in that age bracket are launching businesses and starting over, and while others are retiring, they are no longer just empty nesters.
"We are converting our children's bedrooms into wardrobes, we are changing some rooms into gyms, we are redesigning our home offices - those are interior design opportunities. We are prime for financial planning, now we have some free money. So financial institutions should be knocking at our doors, literally at our feet, saying they want to help us plan our money," she says.
"That is the power of the primetime woman in terms of money. We have a lot of buying power. And do not talk to us the way you talk to the men of the same age as us or other women."
Dr Masitsa intends to ensure that all this and a lot more shine through her representation of the primetime woman on the show. Her favourite Real Housewives show is Real Housewives of Beverly Hills, and her favourite housewife is Lisa Vanderpump, who is no longer on the show. She sees a lot of herself in Vanderpump.