She weeps not for her sire if none be near,
In company she calls up many a tear.
True mourners would not have their sorrows known,
For grief of heart will choose to weep alone.

[Amissum non flet cum sola est Gellia patrem,
Si quis adest, iussae prosiliunt lacrimae.
Non luget quisquis laudari, Gellia, quaerit,
Ille dolet vere, qui sine teste dolet.]

Martial (AD c.39-c.103) Spanish Roman poet, satirist, epigrammatist [Marcus Valerius Martialis]

Epigrams [Epigrammata], Book 1, epigram 33 (1.33) (AD 85-86) [tr. Pott & Wright (1921)]
    (Source)

"On Gellia." (Source (Latin)). Alternate translations:

Gellia ne'er mourns her father's loss,
When no one's by to see,
but yet her soon commanded tears
Flow in society:
To weep for praise is but a feigned moan;
He grieves most truly, that does grieve alone.
[tr. Fletcher (1656)]

When all alone, your tears withstand;
In company, can floods command.
Who mourns for fashion, bids us mark;
Who mourns indeed, mourns in the dark.
[tr. Killigrew (1695)]

Gellia alone, alas! can never weep,
Though her fond father perish'd in the deep;
With company the tempest all appears
And beauteous Gellia's e'en dissolved in tears.
Through public grief though Gellia aims at praise,
'Tis private sorrow which must merit raise.
[Gentleman's Magazine (1736)]

Her father dead! -- Alone no grief she knows;
Th' obedient tear at every visit flows.
No mourner he, who must with praise be fee'd!
But he, who mourns in secret, mourns indeed.
[tr. Hay (1755), 1.34]

Sire-reft, alone, poor Gellia weeps no woe:
In company she bids the torrent flow.
they cannot grieve, who to be seen, can cry:
Theirs is the grief, who without witness sigh.
[tr. Elphinston (1782), Book 6, Part 3, ep. 1]

Gellia, when she is alone, does not lament the loss of her father. If any one be present, her bidden tears gush forth. A person does not grieve who seeks for praise; his is real sorrow who grieves without a witness.
[tr. Amos (1858), #95 "Feigned Tears"]

Gellia does not mourn for her deceased father, when she is alone; but if any one is present, obedient tears spring forth. He mourns not, Gellia, who seeks to be praised; he is the true mourner, who mourns without a witness.
[tr. Bohn's Classical (1859)]

He grieves not much who grieves to merit praise;
His grief is real who grieves in solitude.
[ed. Harbottle (1897)]

Gellia weeps not while she is alone for her lost father; is any one be present, her tears leap forth at her bidding. He does not lament who looks, Gellia for praise;' he truly sorrows who sorrows unseen.
[tr. Ker (1919)]

Gellia, alone, ne'er weeps her sire at all;
In company the bidden tears down fall.
True grief is not for admiration shown.
He only weeps indeed, who weeps alone.
[tr. Francis & Tatum (1924), #18, 1.32]

When alone, Gellia never cries for the father she lost.
If someone is with her, tears well up in her eyes,
as if ordered to fall in. If some one looks for praise,
he is not in mourning, Gellia.
He truly mourns
who mourns
alone.
[tr. Bovie (1970)]

In private she mourns not the late-lamented;
If someone's by her tears leap forth on call.
Sorry, my dear, is not so easily rented.
They are true tears that without witness fall.
[tr. Cunningham (1971)]

Gellia does not cry for her lost father when she's by herself, but if she has company, out spring the tears to order. Gellia, whoever seeks credit for mourning is no mourner. He truly grieves who grieves without witnesses.
[tr. Shackleton Bailey (1993)]

Gellia's mourning for her father?
If by herself she doesn't bother.
But when she sees that company lurks
She opens up the waterworks.
She just wants praise for grief that's shown;
They truly grieve who weep alone.
[tr. Ericsson (1995)]

When Janet is sequestered, out of view,
Then never for her father's death she cries.
But let some viewers come, just one or two,
Then tears dramatically flood her eyes.
We know from this how sad in fact she's been:
It is not grief that's only grieved when seen.
[tr. Wills (2007)]

Gellia doesn't weep for her dead father
when she's alone, but tears pour on command
if someone comes. Who courts praise isn't mourning --
he truly grieves who grieves with none at hand.
[tr. McLean (2014)]

Alone, Gellia never weeps over her father's death;
if someone's there, her tears burst forth at will.
Mourning that looks for praise, Gellia, is not grief:
true sorrow grieves unseen.
[tr. Powell]