Answered by Sidi Mostafa Azzam
I told someone to break her fard make-up fast because she made the intention after fajr and before zuhr. Did I tell her the right thing to do?
Intention for an Obligatory Fast
As you know, in the Shafi`i school, a condition of the intention for an obligatory fast is that it be made before dawn, so there was really nothing for her to break, since her fast was not valid to begin with. (Remember that it is only a non-obligatory fast whose intention can be made up until just before zuhr enters (namely, when the sun reaches its peak).)
Avoiding the Nullifiers of Fasting
When you say you told her to break her fast, if you mean that you told her to engage in a nullifier of fasting (eating, for example), then what you told her is not necessary, since someone not fasting is usually allowed to avoid the nullifiers of fasting, so long as she does not intend fasting by it.
Engaging in an Invalid Act
If you mean that you told her to stop intending fasting, then what you told her is correct, because it is forbidden to deliberately engage in an invalid act, which is what she was doing by meaning to fast while at the same time not fulfilling it validly.
The Hanafi Position
A final word: realize that in the Hanafi school, the intention for an obligatory fast can be made until midday (midway between dawn (fajr) and sunset (maghrib)). To find out the details of that, you should ask Sidi Sheikh Faraz Rabbani (Allah preserve him).
It is generally not advisable to forbid other people things that are allowed in other schools. It suffices you to mention to her, “in the Shafi`i school, a condition of the intention for an obligatory fast is that it be made before dawn,” and let her decide from there what to do.
And Allah knows best.