I think you're wrong. It sounds as if this is a very new friendship/ acquaintanceship and the OP (out of no malice, but because, as she admits herself, doesn't have any friends and has never had any, and is hence (a) totally inexperienced at it and (b) understandably suspicious, because her previous experiences with people haven't gone well) is expecting far too much of someone who is still, presumably, a casual acquaintance, in part because this is, one assumes, the only friendship she's pursuing, and it's almost certainly not for the other person.
I mean, I can see why the OP, given her struggles with friendships, might want to see a particular level of enthusiastic response so she feels reassured the other person isn't rolling their eyes and saying 'Oh, god, a walk with X, I suppose I should go'. I absolutely get that. we've all been there.
BUT, on the other hand, the other person has to want to engage in a new friendship, and being subjected to arbitrary 'tests' as to whether she really wants to go for a walk with the OP, as indicated by a more enthused response, is a bit much at this point.
Bluntly, if I'd said yes to a plan to go for a walk and I knew the person was on the internet complaining that I'd only replied to the time and place with a thumbs up, and that they were thinking of cancelling because I seemed insufficiently enthused, I'd probably disengage gently.
I mean, I have enough stuff going on in my life without my emoji use being interrogated by someone I'm only getting to know. I don't need to be cast in someone else's internal drama.