One could call Liliya weird or crazy because of what she blurted out, but she didn't mind. Even the masked gaze of pity coming from the man whose wife she claimed herself to be, she didn't mind.
Why would she, when she was already enchanted when he had disguised himself as Lucy, a woman, and decided to stay with 'her'.
Although Liliya had affection for Lucas when he was disguised as Lucy and had accepted to join him on his adventure on Lindstrom planet, she still couldn't transfer all that affection towards Lucas, who was also quite different from the persona he mimicked while being Lucy.
Still, they were married. At least she was still the wife. So, she wanted to atleast try to cultivate affection between them once again.
And this chance of fighting together with while protecting each other's back against a common enemy could be a chance that she wouldn't like to miss.