sorry for being totally thick lol but what sort of assets would they be?
Current assets include cash in the bank / any amounts that were invoiced for the work performed in the year, but weren't paid yet. I think fixed assets would be her equipment for filming, as it's long-term in nature.
Basically, without statement of profit or loss, it is hard to determine how much she'd earned in the last year - the increase in net assets is £72k - however, she has most certainly she extracted the money via dividends. I think it's likely that £65k in creditors is the tax due to be paid on profits (so whatever she earned BEFORE she paid dividends), and at 19% corporation, this would mean her profit in 2018/2019 was £342k.
Mark probably started working for her and taking active part as it would otherwise be against tax rules to have him as director / dividends receiver - if it was only Anna who could extract dividends, she would have to pay 38.1% tax on any amount above £150k, and 32.5% on any amounts between 50 and 150k (roughly, haven't checked tax bands lately), while on the first £50k, the dividend tax is about 7% - so bringing Mark into the business makes lot of sense from tax perspective based on estimated earnings over £300k.
I know it seems like a lot of money - just bear in mind it's not like she has the full £300k in the bank, after all the taxes are paid, even with Mark in the business, this is likely to be closer to £200k in net earnings.
(I am in final stages of accounting qualification, so thought I'd help clarify her position a bit since I see there is a bit of confusion around it)