I grew up in a background of family/community involvement strikes, protests and workers rights' and even I am not aware of all the ins and outs of how strikes work, as I've not been in a job where it's come up for me (am self-employed).
However, younger people know less about these things because the world has moved to the right, what was normal is now considered 'leftist' and what was disturbingly far right wing in my youth is now considered bland centrist (or the Labour Party).
The OP voted for the strike to show her support for its cause and would strike if she were not afraid of being unable to cope financially. Those saying 'we all suffer financially' don't know her particular position: some people could end up homeless with children if they get into any more arrears or debt; others might just have a few weeks of one meal a day.
OP, I'd talk to the manager if it were me, explaining how much I want to support the strike, but how scared I am of the consequences for me personally. It's important she understands that not everyone is in a position where they feel able to.
Having said that, we owe the basic rights and freedoms we still have left to the many workers who starved on strikes or were imprisoned or even died in protests to give them to us. I grew up with being a strikebreaker or a scab as the worst sin anyone could commit (really difficult for me atm trying to come to terms with my DH, an academic, not striking).
I just wouldn't judge someone as it can be scary and there isn't often in workplaces the solidarity and sense of community support that, for example, a mining community might have fostered.