Buenos dias, señora

I always greet the people I pass on my walk.  I usually say hello or good morning and people say the same to me.
Today I greeted this lady who was sitting outside her house, but she didn't answer me. In fact I think she didn't see me, she was too concentrated in her own thoughts or perhaps she didn't want to be disturbed. Saying hello would imply that she would have had to wear her face mask.
Who knows?