that Charlotte had a specific end game in mind, as you seem to think i.e Darcy giving htem a living. But I do think she feels that Lizzy might eventually have more influence with Darcy than she had at that time in the novel. And therefore she might possibly be in the position , one day in the future , to be able to do them some good , in some way advancing the Collins's professional interests.

I think Charlotte is very perceptive,especially with regard to Lizzy's character( more so than Lizzy is with her,it must be admitted): there is a phrase in Chapter 32 at which I've always marvelled , but because of spoilers we can't discuss it more here, but let me show it to you and see what you think:

She had once or twice suggested to Elizabeth the possibility of his being partial to her, but Elizabeth always laughed at the idea; and Mrs. Collins did not think it right to press the subject, from the danger of raising expectations which might only end in disappointment; for in her opinion it admitted not of a doubt, that all her friend's dislike would vanish, if she could suppose him to be in her power.

;-)