Or in cases of third-person narration, female central protagonists. Again using this list.
Pride and Prejudice by Jane Austen (with Lizzy Bennet; this is a romance from the 1800s)
Jane Eyre by Charlotte Bronte (with the titular Jane; this is rather a romance from the 1800s)
To Kill a Mockingbird by Harper Lee (with Scout Finch, who is a child)
His Dark Materials by Philip Pullman (with Lyra Belacqua, who is a child)
Little Women by Louisa May Alcott (with Jo March; this is from the 1800s and is somewhat a romance in places, ish)
Tess of the d’Urbervilles by Thomas Hardy (with the titular Tess; this is apparently sexual, ans is from the 1800s)
Well, Shakespeare has a lot of relatively main ladies. But since they’re plays, I can’t count any as narrators or anything.
Rebecca by Daphne du Maurier (with a lady narrator called Mrs. de Winter and also the titular Rebecca is important)
Gone With the Wind by Margaret Mitchell (with Scarlett O’Hara; this is a romance about the 1800s)
Bleak House by Charles Dickens (with Esther Summerson, apparently; this is from the 1800s)
Alice in Wonderland by Louis Carroll (with the titular Alice, who is a child from the 1800s)
Anna Karenina by Leo Tolstoy (with the titular Anna; this is a somewhat a romance from the 1800s)
Emma by Jane Austen (with the titular Emma; this is a romance from the 1800s)
Persuasion by Jane Austen (with Anne Elliot; this is a romance from the 1800s)
Memoirs of a Geisha by Arthur Golden (with Chiyo Sakamoto)
Anne of Green Gables by L. M. Montgomery (with the titular Anne, who is a child from the 1800s)
The Handmaid’s Tale by Margaret Atwood (with Offred)
Atonement by Ian McEwan (with Briony Tallis; this has a lot of romance)
Sense and Sensibility by Jane Austen (with Elinor Dashwood; this is a romance from the 1800s)
The Lovely Bones by Alice Sebold (with Susie Salmon)
Bridget Jones‘s Diary by Helen Fielding (with the titular Bridget; this is a romance)
The Secret Garden by Frances Hodgson Burnett (with Mary Lennox, who is a child in the 1800s)
Vanity Fair by William Makepeace Thackeray (with Amelia Sedley and Becky Sharp; this is a romance from the 1800s)
The Color Purple by Alice Walker (with Celie)
Madame Bovary by Gustave Flaubert (with the titular Emma Bovary; this is a romance from the 1800s)
A Town Like Alice by Nevil Shute (with Jean Paget)
28 of 100 titles, because I’m not counting “groups of protagonist” stories like The Chronicles of Narnia or something. Interestingly, 15 of them are about and/or from the 1800s, 5 are about children, and 4 are by Jane Austen.
–your fangirl heroine.