Hi joanna, Ladies!
I am a Mixie (this is a term my sister came up with when she was in high school), and my parents were doing this when there weren't even products out (or thought of) for mixies.
Here is what I can tell you about MY hair and how it may relate to your childrens':
Their hair will often thicken as they get older and the curls may become more defined or may relax into waves! If their hair is thick, it will probably get thicker!
As an adult, I have to change hair care products every few years because they just don't work as well as they used to.
The needs of my hair have changed.
The Luster's Pink Lotion that you googled is the correct product that was written about! I used that growing up, but found that it was too heavy for my hair and gave it a greasy feeling. They make a "lite" version of their product, but I found that to be to heavy also.
Hair grease, any kind, is also too much for my hair, but my sister uses it and it works for her. If you use it, you will probably (I suggest) have to wash your child's hair a little more frequently.
You may notice that your child's hair has a "smell" to it. I would suggest to wash it a little more frequetly.
While a white woman's hair will often "oil up" every day or two, most black women's hair does not. While most white women wash their hair every day or every other day, many black women can go two weeks or longer without washing their hair and still keeping it healthy--it takes longer to naturally produce oil. When I was growing up, my hair would not produce oil for days, then all of a sudden it would be very oily! Play around with it a little bit to get the right rhythm of when to wash your child's hair.
These are generalizations and are not true of every woman. And likewise, your babies' hair all has a different texture. the finer and or softer it is, the less product you will likely have to use.
Mine is thick, thick, thick, but soft and slippery--it doesn't hold braids (or anything else for that matter) for very long. Also, as a mixie, my hair has never grown down, always out and takes about 2-3 days to produce natural oils. My hair also has a VERY Distinct personality all it's own and kind of does what it wants when it wants ;-)
I keep it natural (as opposed to chemically straightening it) and use a light, natural oil on it every other day! Sometimes I will add a light product that helps define the curls. A light mousse usually does the trick. But usually, I just let my hair do it's own thing (and I keep it short enough that this s okay)
Speaking of chemically straightening hair, it is called a relaxer or a perm, when a woman of color gets her hair chemically straightened. Note that for most white women, a "perm" means adding a curly texture to their hair. I'm not exactly sure why the same term is used for the opposite effect, but it is. So when a black woman says that she just got a perm, she just got her hair straightened. If she says she just got a "touch-up", she already keeps her hair straight and "permed" her roots, to straighten them as well. This is a process many black women go through every 6-8 weeks or so.
I also found that as far as shampoo and conditioners go, my family thinks we are cursed because everytime we found a product we liked and that worked well on our hair, it got taken off the market.
However, there are MANY more mixed race children today than when I was growing up, so more products are being created. As with anything concerning your child, do your research and make sure the product you are trying is going to work for the needs of their hair.
I hope this helps all ladies raising little mixie children :-)