With coronavirus social distancing rules in mind, Mrs Britt's extended family did the next best thing they could think of to mark the day. They made signs and stood outside the fence at Mercy Place, a residental aged care village in Ballarat where Margaret lives, and exchanged elbow taps through the fence.

"We are quite a big family and we had planned on having an extended family gathering at the Wallace Hotel on Sunday, but obviously thought the better of it given the circumstances," said daughter Jenny.

Mercy Place currently allow no more than two visitors at a time, and one visit a day, so that wasn't going to work for the family either.

Under current restrictions, children under 16 are only allowed to visit by exception, and all visits must take place in a resident's room, outdoors or a specific area that is not a communal space.

The third option to take the great grandmother out for the day was too risky given the large number of her extended family, which numbers about 30.

When a fourth option to make birthday signs occurred to Jenny as she was unpacking flat-pack furniture, the family jumped at it.

"I had lots of cardboard so thought about putting together signs and calling outside mum's room at Mercy Place, which happens to adjoin the fence line, so that's what we did!"

"It was the best we could do in the circumstances."