Learn Hardcore French: Sur son blog, elle explique ses recettes et raconte des histoires sur sa famille. - On her blog, she explains her recipes and tells stories about her family.

dans son blog would sound like inside her blog (not natural in French here).
à son blog would be ungrammatical; à is not used that way with blog.

So sur is the normal preposition for web pages, blogs, platforms, etc.

Why is it son blog even though elle is feminine? Shouldn’t it be sa blog?

French possessive adjectives (son, sa, ses) agree with the gender and number of the noun possessed, not with the gender of the owner.

le blog = masculine singular noun → son blog (her blog / his blog)
la maison = feminine singular noun → sa maison (her house / his house)
les livres = plural noun → ses livres (her books / his books)

So even though the owner is elle (a woman), we say son blog because blog is masculine.

Why is the present tense (elle explique, elle raconte) used? Does it mean she is doing it right now?

The French présent de l’indicatif covers both:

Something happening now
- Elle explique la recette en ce moment. – She is explaining the recipe right now.
A habit or general activity (like the English “she explains / she tells”)
- Sur son blog, elle explique ses recettes et raconte des histoires…
  = She regularly does this on her blog.

In this sentence, the present tense indicates her usual activity, not necessarily what she is doing at this exact moment.

What exactly does recettes mean here? Could it mean “receipts”?

In French:

une recette most commonly means a recipe (for cooking).
It can also mean takings / revenue / income in some contexts (e.g. la recette du cinéma = the cinema’s takings).
It does not mean receipt in the everyday sense of a shop receipt. That’s un reçu or un ticket de caisse.

Given the context sur son blog and pairing with explique ses recettes, it clearly means cooking recipes here.

Why is it ses recettes and not les recettes?

The choice between ses and les changes the nuance:

ses recettes = her recipes (the ones that belong to her / that she created or uses)
les recettes = the recipes (all the recipes in general, or some specific set already known from context)

In the sentence, we want to say she explains her own recipes on her blog, so ses is the natural choice.

Why is it ses recettes (plural) and not sa recette (singular)?

Because we’re talking about her activity in general on her blog:

ses recettes = many different recipes she explains over time.
sa recette would sound like she explains one single recipe, which doesn’t fit the idea of an ongoing blog.

So the plural matches the idea that she shares multiple recipes.

What is the difference between explique ses recettes and raconte des histoires? Why two different verbs?

The verbs emphasize different kinds of content:

expliquer = to explain, to make something clear, give instructions, teach how it works.
- elle explique ses recettes → she explains how to make her recipes, the steps, the method.
raconter = to tell, to narrate, used for stories, anecdotes, events.
- elle raconte des histoires → she tells stories (narratives), not instructions.

So the sentence contrasts:

practical explanation (recipes)
with
narrative storytelling (family stories).

Why is it des histoires and not les histoires or ses histoires?

des histoires = (some) stories, non-specific, general. It just says that she tells stories, without specifying which ones.
les histoires = the stories, a specific, already-known set of stories.
ses histoires = her stories, emphasizing that they are her stories (e.g. that she invents or owns them).

Here the focus is not on ownership of the stories, but on the fact that she tells stories about her family in general. So des histoires is the most natural choice.

Why is it des histoires sur sa famille and not des histoires de sa famille?

In this context:

des histoires sur sa famille = stories about her family
→ The family is the topic of the stories.
des histoires de sa famille is possible but has a different primary feel:
- It can mean stories that come from her family (family legends, things they tell each other),
- or, depending on context, even stories told by her family.

To clearly express about her family as a subject, French prefers:

des histoires sur sa famille
or des histoires à propos de sa famille
or des histoires au sujet de sa famille

In modern, everyday style, sur = about is very common.

Does sur sa famille always mean “about her family”? I thought sur meant “on”.

sur has several meanings, including:

on / onto / on top of (physical location)
- Le livre est sur la table. – The book is on the table.
about / concerning (topic)
- un film sur la guerre – a film about the war
- un livre sur les oiseaux – a book about birds
- des histoires sur sa famille – stories about her family

So here sur is used in the “about (a topic)” sense, which is very common with books, films, articles, stories, etc.

Can I change the word order and say Elle explique ses recettes et raconte des histoires sur sa famille sur son blog?

Yes, that sentence is grammatically correct, but the emphasis changes slightly.

Sur son blog, elle explique…
Starts with “On her blog”, highlighting the place first.
Elle explique ses recettes et raconte des histoires sur sa famille sur son blog.
Mentions sur son blog only at the end; the focus is first on what she does, and only then where she does it.

Both are natural. The original version simply foregrounds the blog as the setting.