Did you ask her?
Did she remove all the hosts and extinguish the tabernacle light?
Maybe she was removing hosts to bring Holy Communion to patients at your local hospital. Did you include this woman in your prayers? Did you include any sick or diabled parishioners in your prayers? Did you praise Our Lord as He was being carried from the tabernacle by this woman? He remained Our Lord in her pyx.
I realize it’s terribly annoying to have one’s prayers interrupted, but unless this is your own private chapel, the tabernacle belongs to the parish. There are times in an adoration chapel that people enter the chapel in order to change the flowers, replace the candles, vacuum, etc. and it’s very disruptive to my prayer and meditation, so I sympathize with your situation. Our prayer time should be respected. But it isn’t my personal, private adoration chapel, and flowers do need to be watered, candles replaced, the chapel cleaned, etc.
I’m an EMHC and if I needed to remove or replace hosts in the tabernacle while someone close by was obviously deep in prayer, I would have quietly and gently said “Excuse me, but would it be too disruptive if I filled my pyx? I’ll only be a moment. Sorry to interrupt your prayers.” It’s possible that this woman hesitated to speak to you because she didn’t want to interrupt you, and might have thought she’d be less of a distraction if she worked silently, although that wasn’t the case. At the same time, if someone asked me if I needed to be there at that time, I wouldn’t have taken offense, I would have politely said something like: “I’m filling my pyx to bring Our Lord to patients at County Medical Center.”
Maybe it would help to consider this: Someday you might be grateful to see this very same woman coming to visit you if you’re ill or have had an accident and can’t attend Mass.
When we pray in a church, it’s good for all of us to remember that we are praying in community with others and for others. Our Lord is for all at all times.