what is the suitable preposition

Depending upon factors like the child's age .... this may be an
impossible task or conversation to get into. At certain ages most
children simply cannot fathom such a topic - let alone its importance
so it is ridiculous to them. For a late high school/early college student
you would no doubt be understood; even if he or she totally disagreed
with what you are saying.
BUT when considering this question from the standpoint of: is it okay?
/is it right?/is it helpful?? - - to say this to a child - - one has to consider
the motive behind this "little lecture on life". As a child grows and
matures, ideally they must learn their conduct is primarily a reflection
upon themselves & of the choices THEY have made." To finally learn
& come fully to terms with the intimate concept of what personal
responsibility truly IS as well as the meaning & importance of
"THE EXAMINED LIFE" is of the utmost importance in order for
ME to continue to grow & learn as I grow older in years. One never stops.
To look at my own life, I am 60 years old, my parents are long gone
& how I behave reflects upon no one & nothing but me, myself & I
I remember that period of time when my 3 daughters were young girls
and how I struggled with the concept that every action of theirs was
a reflection of me as a parent. A kindly pastoral family therapist was
able to help me let go of MY erroneous assumptions so I could begin
to teach them (before it was too late) that their life choices as they
grew older - were theirs to make as well as theirs to accept full
responsibility for, and it was MY JOB to learn that their life choices
did NOT necessarily reflect upon me at all.

I would say that it would depend on the words chosen after "speak + preposition", Bubu.

Forget about all those external influences.
Kids don't care.

Just say:
"What you do says a lot about yourself. Be sure it's what you want to say."

*******************************

But if you insist on keeping your original sentence, I'd say

. . . speaks to HOW you were raised, HOW you see yourself, and WHAT . . .

Goodness Gracious!!
I just wanted to know the use of a suitable preposition after the verb 'speak'. You guys have stretched it out so far!!!

Certain words and certain phrases tend to collocate with certain prepositions, Bubu. I understand what you're saying re Bats-something or other but Punkey actually addressed your question and I will certainly attempt to do the same when you supply some of your own ideas.