So, the argument is that "Avocados are good for your skin." However, the word "good" in itself is subjective. So, let's look at the claims she uses in the article. She states 12 different claims on how avocados can be good for your skin. If one or two of these are correct, and there isn't any harm to your skin; then I could say, "avocados are good for your skin".
First, this is a blog backed a "medically backed spa" as they say. The author is a physician's assistant and majored in Biology. She's working on her medical science degree. You can find this info on the blog's about page: Kristina Cadwell
Pretty solid, but let's go further, she references a small research study on the effects of avocado on women's skin, which you can find here: Avocado Consumption Increased Skin Elasticity and Firmness in Women ‐ A Pilot Study - PMC
The study is part of the National Library of Medicine which is as credible a source as I think you can get for information on this. However, the study only looked at the effects in 30 women.
Next, we can look at a less credible source, Medical News Today, which uploaded a similar article in 2018, 6 years before Caldwell's article. So, this information isn't new, but the point is it has had time to be debunked - otherwise I don't think Caldwell would risk her career on old news. Here is the article here: Avocado oil for skin: 8 benefits and how to use it. This also has been medically reviewed. You can do with that what you will.
All in all, "good" is subjective, but Caldwell backs up her claims with solid research on a couple of the points.
Here is also a Harvard public health source on the vitamins and minerals in Avocados which back up Caldwell's first claims about vitamins being good for the skin: Avocados – The Nutrition Source
These sources coupled with the absence of articles on avocados being conversely bad for your skin, indicates to me she is telling the most truth she knows for a relatively low researched topic.
Is it highly backed by a lot of science? No. Is it purposely trying to make you believe something that is not true? Also no. I think its new research, and what they know so far, is yes, avocados are indeed good for the skin.
Now is that internally or topically? Depends on the point she is making, as she makes 12 that would each have to be researched.
But I think her overall point is true based on these sources I found.