She has some nerve and arrogance to compare her situation to that of other single parents. First of all, she never was a single mother in the classical sense, she never had to "run" the family completely on her own, she was always co-parenting with Matt and only had 50% of the responsibility, 50% of the financial burden, etc. When she met Liam, she was financially independent with a high income, and she had a lot of freedom to do whatever she wanted, including travelling, going out, and dating. Yes, of course she had to think of Darcy and be responsible about introducing a new partner to her, but in what way was she not a "good package"? She was probably just scared that she'd never find another man who is spineless enough to put up with her bullshit on a daily basis. It's not like she was faced with the stereotypes and challenges that single mums have to deal with, prejudices and accusations like they're only looking for a man to finance their lifestyle, and so on.