It is your right to ask someone not to talk about a subject in front of your child. On the other hand your child will come across such ideas in her life and it is an opportunity to discuss it with her from a biblical perspective.
That your children will come across this one day is not the same as a trusted adult in charge, claiming to be a Christian, teaching this as fact. So it's not really a valid comparison at all.
I do have a personal view on astrology. I think it is a sin to look into horoscopes as a means to know the future. I never read horoscopes. My dad (who was not saved at the time) used to write them for a magazine and he made it all up and found it hilarious when people came up to him asking for a personal one.
I do have perhaps an unorthodox view though. I do believe that astrology is very real and that it is God's very functional and even mathematical way of allocating aspects of personalities, gifts and even certain paths and events in our lives in an amazing way that doesn't impact our free will or genetically inherited traits.
I believe that any information astrologers have is only partial - which is why it is not very reliable. I think demons have limited knowledge of it too and have shared this knowledge with man but the knowledge is incomplete. Only God has complete knowledge about the workings of planetary/astral alignment and its effect in our lives. It is to be hidden (occult) which is why God commands thus.
Personally I do think that the limited knowledge we do have on astrology can occasionally be helpful in terms of understanding aspects of another person's personality - but not for fortune telling. I am guilty of working out people's birthdays and their star sign and it does give me a little insight into some aspects of their personality. However, I have never mentioned it to my children or discuss such things in front of them. I will never encourage my children into astrology or anything occult that the Lord commands to remain hidden.
So your view is that, despite it being forbidden in the bible, it is still of God. That the alignment of the stars in the sky dictates what kind of person we will be, what kinds of choices we should make and generally over the affairs of the world, despite it being forbidden in the bible.
The issue i have with this idea that there is any validity in it is that the concept is flawed from the beginning. The stars are not really in different places. The earth is spinning and orbiting, and the gives the illusion that the stars around us are shifting. But in reality nothing is really changing, not in the way astrology implies. So, by the very nature of the idea, it disproves itself from the start.
And taking on an idea that this is a Godly thing, yet He forbids us of having knowledge of... actually calls an 'abomination' (defined as 'extreme disgust and hatred). But this thing He forbids and refers to as causing Him disgust and hatred over it, came from Him? Is rooted in Him? I should think that anything that causes God 'disgust and hatred' toward it is not something that stems from Him at all.