If you want my honest opinion, I don't think she will ever get a visit visa. She is a minor with both of her parents living in the UK on whom she is dependent financially. There is nothing at all she can do to demonstrate that she has stronger ties to the Philippines than the UK, because that simply isn't the truth of the situation.
The sooner she gets to the UK as your spouse visa dependent, the better. She can continue on as a spouse visa dependent if she turns 18 whilst in the UK, but ONLY if she started on a dependent visa before her 18th birthday, and in that time (the 5 years between the initial visa and her eligibility for settlement), she needs to still be a member of your household. She can't have formed an independent life in that time.
I am not an immigration adviser and my opinions should not be construed as legal advice. Please do not PM me for advice.