As you both have a common interest - ie a child, it will be difficult to convince creditors that you are both financially independent, and therefore I feel that you are being appropriately advised at present.
In such circumstances, your partner will have to be content that her disposable income is used to assist with ongoing payments, and if she does not agree to this then perhaps you ought to look to other solutions such as bankruptcy or debt management.
Over the last few years creditors have become more and more alert to the fact that debts taken out solely are actually incurred to fund shared expenditure. Whilst this may or may not be the case, there is a hardening of attitiude towards allowable expenditure under IVA proceedings, that is not flowing through to bankruptcy or debt management.
Regards, Melanie Giles, Insolvency Practitioner