Also on the subject of Cirstea, the fact that she won titles during her teens and her 30s, but 0 during her 20s (only reaching 2 finals during her 20s most notably in Toronto in 2013), stands out.
There can't be too many other examples of that. Mirjana Lucic was another example, winning her titles as a 15 and 16 year old in Bol in 1997 (her WTA tournament debut) and 1998, and then as a 32 year old in Quebec beating Venus in the final. The 16 year and 4 month gap between her 2nd and 3rd title really stood out.
But Cirstea played in significantly more tour level matches in-between her title wins in Tashkent in 2008 and Istanbul in 2021, than Lucic did in-between her title wins in Bol in 1998 and Quebec in 2014 (with her suffering well documented personal issues and financial problems, and her lengthy hiatus).
Arantxa Rus winning a title as a 32 year old at Hamburg in 2023, after never previously reaching a tour level final (she was well known in tennis circles for her truckload of titles at challenger / ITF level), was also notable.