Two soft-shelled eggs in a row?

[SCOUT123]

I have an almost 18-month-old RIR hen. She's laid two soft shelled eggs in a row. Should I supply her with more calcium (what should I do?)

 

[Pork Pie]

Here's a link that may help -
http://www.backyardchickens.com/a/common-egg-quality-problems