Upvote:1
You mention grounds for refusal included no evidence that she will leave the UK at the end of the visit. She needs to show that she has strong ties to her home country such as regular employment. A current account in her home country may also help.
Upvote:6
As far as UK Visitor Visas go, there is no time limit that a person must wait after a refusal before applying again. The applicant is, however, always advised that they should address and remedy the grounds for the refusal before applying again, but this is not a requirement.
She will also have to think up something to say about her prior refusal. Based upon what you wrote, it is unlikely that the ECO would look favourably on someone by accident submitting the wrong bank statements, because people do not do that very often. More often applicants do this in order to improve their circumstances. The ECO might be likely to conclude that your daughter did not understand what was required (and thus not understand the conditions of the visa). Or perhaps they could issue the visa without question, nobody knows. In all events, her explanation should be convincing.
Evidence of not understanding the rules, or not understanding the requirements, or in some other way not showing full capacity works AGAINST the applicant.
For your other question, 'is it ok to buy ticket(s) before getting visa'? The UK Foreign Office (in various incarnations) has run an advisory on their site since the beginning of Internet that applicants should NOT purchase tickets in advance. Doing so is likely to indicate that the applicant has not read the requirements or does not understand them. Purchasing tickets in advance of an approved entry clearance is emphatically not recommended.