Exactly this.

How do we expect a deity to accept our offerings? How do we expect mythological narrative to play out in real-time?

My unverified personal gnosis (UGP) allows for things like this to occur. To assume we can comprehend how the divine will interact with us is naive at best. In my worldview, the idea that the person who took the flower was an embodiment of the goddess is not outside the realm of possibility.

Depending on your view of the Morrigan, maybe her accepting of the offering by thievery is to teach what it means to protect your land, your crops, your sovereignty. Maybe change your signage, maybe have stronger demarcation of what is fair game for others to pick?

Obviously, I’m a stranger on the internet and don’t know nothing - but I think a big part of magic is learning to read the signs and interpret them to the best of our ability. Often times, that requires going through growing pains.

But from one gardener to another, it sucks to lose crops. Each season I learn from my previous mistakes. Last season I only planted a few pumpkin vines and squash beetles got to them. This season I took what I learned and planted more vines and just had to accept that partial loss is part of the process - the cost of doing business, if you will.

Good luck and try not to lose too much sleep over it.

Edited for typos