You've only given us the vaguest of outlines of the case. However if, as it's beginning to read like, it involves knife crime against a child, you can forget about reading all of the fine print in the guidelines. I'll tell you now (categorically) that the judge will be fully satisfied that the 'custody threshold' test has been passed. (i.e. the judge WILL pass a custodial sentence).
However he/she will then have to apply the second test, which requires him/her to consider whether the sentence can be suspended. That will depend upon factors that we've no knowledge of, such as the previous criminal history of the offender (if any), the level of remorse shown, the likelihood of reoffending (as assessed by the probation service), the likelihood of the offender complying with any requirements to, for example, undertake unpaid work (again, as assessed by the probation service), etc.